In the last decade, preoperative modelling of the treatment of cerebral aneurysms is being actively developed. Fluid-structure interaction problem is a key point of a such modelling. Hence arises the question about the reasonable choice of the model of the vessel and aneurysm wall material to build the adequate model from the physical point of view. This study covers experimental investigation of 8 tissue samples of cerebral aneurysms and 1 tissue sample of a healthy cerebral artery. Results on statistical significance in ultimate stress for the classification of 2 cohorts of aneurysms: ruptured and unruptured described earlier in the literature were confirmed (p ≤ 0.01). We used the four most common models of hyperelastic material: Yeoh, Neo-Hookean and Mooney-Rivlin (3 and 5 parameter) models to describe the experimental data. In this study for the first time, we obtained a classification of hyperelastic models of cerebral aneurysm tissue, which allows to choose the most appropriate model for the simulation problems requirements depending on the physical interpretation of the considered problem: aneurysm status and range of deformation.

The study demonstrated superior clinical outcomes for endovascular flow diversion in comparison with bypass surgery in treatment of complex aneurysms. Though, both techniques grant similar percentage of major neurologic complications and comparable cure rate for cranial neuropathy. Nevertheless, flow diversion is associated with significantly lower early obliteration rate, thus possesses patient for risks of prolonged dual antiplatelet regimen and delayed rupture. Hence, it's important to stratify patient by the natural risk of aneurysm rupture prior to treatment selection.

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Implementation of a large number of surgeries enabled improvement of the technique and clarification of the prerequisites for preoperative examination, intraoperative control, and postoperative management of patients. A low mortalits rate suggests this technique for use in clinical practice. The surgery is indicated for the treatment of giant aneurysms of the petrous, cavernous, and clinoid segments of the ICA. In the case of giant supraclinoid aneurysms, the surgery may be combined with removal of thrombotic masses from the aneurysm sac for rapid decompression of the cranial nerves. Application of this surgery for treatment of giant aneurysms of the trunk and bifurcation of the basilar artery is promising but requires further investigation. The surgery is also recommended for improving cerebral perfusion in the setting of complex stenotic occlusive lesions of the BCA: prolonged BCA stenoses, tandem ICA stenoses located in both the extracranial and intracranial segments, nonspecific vasculitis and arteriitis, subcranial aneurysms, kinking etc.

In practical neurosurgery, an important issue is determining the status of the aneurysm and predicting its further growth, rupture or stabilization. The main approaches for the study of risk analysis asessment are computational hydrodynamics and analysis of the mechanics of the wall of cerebral aneurysm. In this paper, an analysis of various sections of the wall of cerebral aneurysm is given, combining mechanical test data and histological examination data. It was shown that, along with significant differences in mechanics, a different degree of calcification is observed in the tissue, which indicates a different level of impaired transport of substances inside the tissue.

Оперативное лечение дистальных аневризм экстракраниального отдела внутренней сонной артерии, сочетающихся с ее патологической извитостью К.м.н. в.Э. ГУжиН, а.в. ДУБовой, а.в. череПаНов ФГБУ «Федеральный центр нейрохирургии» минздрава россии, Новосибирск, россия аневризмы экстракраниального отдела внутренней сонной артерии (вса), расположенные у входа в череп, являются редкой патологией. При данной патологии показано проведение хирургического вмешательства из-за опасности артерио-артериальной эмболии с развитием нарушения мозгового кровообращения. в отечественной и зарубежной литературе представлены единичные случаи или небольшие по числу наблюдений группы успешного хирургического лечения пациен-тов с дистально расположенными аневризмами внутренней сонной артерии в сочетании с ее патологической извитостью. открытое оперативное вмешательство при этой локализации аневризмы является сложным из-за травматичности доступа. Проведение эндоваскулярных вмешательств не всегда возможно из-за наличия дегенеративных изменений сосудистой стенки и патологической извитости артерии. Предложен вариант хирургического вмешательства по созданию экстраана-томического высокопотокового шунта между наружной сонной артерией и м2 сегментом среднемозговой артерии. Пред-ставлены результаты успешного применения данной методики у 3 пациентов с дистально расположенными аневризмами экстракраниального отдела внутренней сонной артерии в сочетании с ее патологической извитостью. Ключевые слова: патологическая извитость артерий, аневризма, внутренняя сонная артерия, высокопотоковый шунт. Surgical treatment of distal extracranial internal carotid artery aneurysms associated with pathological artery kinkingv.E. Guzhin, a.v. DuBovoY, a.v. chErEPanov Federal center of neurosurgery, novosibirsk, russia Extracranial internal carotid artery (ica) aneurysms located at the entrance of the skull are a rare pathology. Surgical treatment is indicated for this pathology because of the risk of arterio-arterial embolism and the development of cerebrovascular disease. the domestic and international literature reports single cases or small group cases of successful surgical treatment of patients with distal internal carotid artery aneurysms associated with pathological kinking of the artery. open surgery for aneurysms of this localization is complicated because of a high injury risk associated with the approach. Endovascular interventions are not always possible due to the presence of degenerative changes in the vascular wall and pathological artery kinking. We propose a surgical option for creating a high-flow ec-ic bypass between the external carotid artery and the m2 segment of the middle cerebral artery. the article describes the results of successful application of this technique in three patients with distal extracranial internal carotid artery aneurysms associated with pathological kinking of the artery.

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Currently, several materials for the closure of the dura mater (DM) defects are known. However, the long-term results of their usage reveal a number of disadvantages. The use of antibiotics and chitosan is one of the major trends in solving the problems associated with infectious after-operational complications. This work compares the mechanical properties of samples of bacterial nanocellulose (BNC) impregnated with Novochizol™ and vancomycin with native BNC and preserved and native human DM. An assessment of the possibility of controling the mechanical properties of these materials by changing their thickness has been performed by statistical analysis methods. A total of 80 specimens of comparable samples were investigated. During the analysis, the results obtained, the factor of Novochizol™ addition has provided a statistically significant impact on the strength properties (Fisher Criteria p-value 0.00509 for stress and 0.00112 for deformation). Moreover, a stronger relationship between the thickness of the samples and their ultimate load was shown: R2=0.236 for BNC + Novochizol™ + vancomycin, compared to R2=0.0405 for native BNC. Using factor analysis, it was possible to show a significant effect of modified chitosan (Novochizol™) on the ultimate stress (p-value = 0.005).