scholarly journals Hemodynamic factor evaluation using computational fluid dynamics analysis for de novo bleb formation in unruptured intracranial aneurysms

2021 ◽  
Author(s):  
Takehiro Uno ◽  
Kouichi Misaki ◽  
Kazuya Futami ◽  
Iku Nambu ◽  
Akifumi Yoshikawa ◽  
...  
Keyword(s):  
High Pressure ◽  
Statistical Analysis ◽  
Intracranial Aneurysms ◽  
De Novo ◽  
Fluid Dynamic ◽  
Multipoint Method ◽  
Unruptured Intracranial Aneurysms ◽  
Computational Fluid Dynamics Analysis ◽  
Risk Of Rupture ◽  
Bleb Formation

Abstract Background Although bleb formation increases the risk of rupture of intracranial aneurysms, previous computational fluid dynamic (CFD) studies have been unable to identify robust causative hemodynamic factors, due to the morphological differences of prebleb aneurysm models and a small number of aneurysms with de novo bleb formation. This study investigated the influences of differences in the aneurysm-models and identify causative hemodynamic factors for de novo bleb formation. Materials and methods CFD analysis was conducted on three aneurysm models, actual prebleb, postbleb, and virtual prebleb models of two unruptured aneurysms with de novo bleb formation. A new multipoint method was introduced in this study. We evenly distributed points with a 0.5-mm distance on the aneurysm surface of the actual prebleb models (146 and 152 points in the individual aneurysm, respectively), and we statistically compared hemodynamics at the points in the areas with and without bleb formation (19 and 279 points, respectively). Results Visually, blebs formed on an aneurysm surface area with similar hemodynamic characteristics in the actual and virtual prebleb models. Statistical analysis using the multipoint method revealed that the de novo bleb formation area was significantly correlated with high pressure (p < 0.001), low wall shear stress (WSS) (p < 0.001), and the center of divergent WSS vectors (p = 0.025). Conclusions De novo bleb formation in intracranial aneurysms may occur in areas associated with the combination of high pressure, low WSS, and the center of divergent WSS vectors. The multipoint method is useful for statistical analysis of hemodynamics in a limited number of aneurysms.

scholarly journals Long-term outcomes of coil embolization of unruptured intracranial aneurysms

2018 ◽  
Vol 129 (6) ◽  
pp. 1492-1498 ◽  
Author(s):  
Masaomi Koyanagi ◽  
Akira Ishii ◽  
Hirotoshi Imamura ◽  
Tetsu Satow ◽  
Kazumichi Yoshida ◽  
...  
Keyword(s):  
Coil Embolization ◽  
Intracranial Aneurysms ◽  
Additional Treatment ◽  
Long Term Outcomes ◽  
Unruptured Intracranial Aneurysms ◽  
Risk Of Rupture ◽  
Long Term Follow Up ◽  
Multiple Stroke

OBJECTIVELong-term follow-up results of the treatment of unruptured intracranial aneurysms (UIAs) by means of coil embolization remain unclear. The aim of this study was to analyze the frequency of rupture, retreatment, stroke, and death in patients with coiled UIAs who were followed for up to 20 years at multiple stroke centers.METHODSThe authors retrospectively analyzed data from cases in which patients underwent coil embolization between 1995 and 2004 at 4 stroke centers. In collecting the late (≥ 1 year) follow-up data, postal questionnaires were used to assess whether patients had experienced rupture or retreatment of a coiled aneurysm or any stroke or had died.RESULTSOverall, 184 patients with 188 UIAs were included. The median follow-up period was 12 years (interquartile range 11–13 years, maximum 20 years). A total of 152 UIAs (81%) were followed for more than 10 years. The incidence of rupture was 2 in 2122 aneurysm-years (annual rupture rate 0.09%). Nine of the 188 patients with coiled UIAs (4.8%) underwent additional treatment. In 5 of these 9 cases, the first retreatment was performed more than 5 years after the initial treatment. Large aneurysms were significantly more likely to require retreatment. Nine strokes occurred over the 2122 aneurysm-years. Seventeen patients died in this cohort.CONCLUSIONSThis study demonstrates a low risk of rupture of coiled UIAs with long-term follow-up periods of up to 20 years. This suggests that coiling of UIAs could prevent rupture for a long period of time. However, large aneurysms might need to be followed for a longer time.

Management of carotid artery stenosis in patients with coexistent unruptured intracranial aneurysms

2020 ◽  
Vol 132 (1) ◽  
pp. 94-97 ◽  
Author(s):  
Tiziano Tallarita ◽  
Thomas J. Sorenson ◽  
Lorenzo Rinaldo ◽  
Gustavo S. Oderich ◽  
Thomas C. Bower ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Carotid Artery Stenosis ◽  
Intracranial Aneurysms ◽  
Early Period ◽  
Aneurysm Rupture ◽  
Artery Stenosis ◽  
Consecutive Series ◽  
Carotid Revascularization ◽  
Unruptured Intracranial Aneurysms ◽  
Risk Of Rupture

OBJECTIVEConcomitant unruptured intracranial aneurysms (UIAs) are present in patients with carotid artery stenosis not infrequently and result in unique management challenges. Thus, we investigated the risk of rupture of an aneurysm after revascularization of a carotid artery in a contemporary consecutive series of patients seen at our institution.METHODSData from patients who underwent a carotid revascularization in the presence of at least one concomitant UIA at our institution from 1991 to 2018 were retrospectively reviewed. Patients were evaluated for the incidence of aneurysm rupture within 30 days (early period) and after 30 days (late period) of carotid revascularization, as well as for the incidence of periprocedural complications from the treatment of carotid stenosis and/or UIA.RESULTSOur study included 53 patients with 63 concomitant UIAs. There was no rupture within 30 days of carotid revascularization. The overall risk of rupture was 0.87% per patient-year. Treatment (coiling or clipping) of a concomitant UIA, if pursued, could be performed successfully after carotid revascularization.CONCLUSIONSCarotid artery revascularization in the setting of a concomitant UIA can be performed safely without an increased 30-day or late-term risk of rupture. If indicated, treatment of the UIA can take place after the patient recovers from the carotid procedure.

scholarly journals Estimating the annual rate of de novo multiple aneurysms: three statistical approaches

2004 ◽  
Vol 17 (5) ◽  
pp. 1-8 ◽  
Author(s):  
James Ju Yong Cheong ◽  
Narcyz Ghinea ◽  
James M. van Gelder
Keyword(s):  
Intracranial Aneurysms ◽  
De Novo ◽  
Annual Rate ◽  
Rate Of Development ◽  
Multiple Intracranial Aneurysms ◽  
Multiple Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
Study Heterogeneity ◽  
Age Stratification

Object Individuals with unruptured intracranial aneurysms experience a higher rate of rupture if their history includes another aneurysm that has previously bled. The authors used systematic review and metaregression to estimate the annual rate of development of second de novo aneurysms after subarachnoid hemorrhage. Methods This investigation included studies in which more than 300 patients with intracranial aneurysms were described, and in which the age of the patients and the proportion with multiple aneurysms were documented. Studies describing delayed follow-up angiography that was performed after treatment of aneurysms were also reviewed. Twenty studies were included in a between-study analysis. The univariate odds ratio (OR) for multiple intracranial aneurysms per year of age was 1.085 (95% confidence interval [CI] 1.015–1.165); this value was calculated using a hierarchical model for between-study heterogeneity. Five studies were included that provided age stratification. The estimated OR for multiple intracranial aneurysms per year was 1.011 (95% CI 1.005–1.018). Four follow-up studies were available. Conclusions According to the three different approaches (study-level, patient-level, and follow-up analyses), the estimated annual rates of development of de novo aneurysms were 1.62% (95% CI 0.28–3.59%), 0.28% (95% CI 0.12–0.49%), and 0.92% (95% CI 0.64–1.25%), respectively. The estimated annual rate of development of second de novo aneurysms ranged from 0.28 to 1.62%.

scholarly journals Risk of Rupture of Unruptured Intracranial Aneurysms in Relation to Patient and Aneurysm Characteristics

Stroke ◽  
2007 ◽  
Vol 38 (4) ◽  
pp. 1404-1410 ◽  
Author(s):  
Marieke J.H. Wermer ◽  
Irene C. van der Schaaf ◽  
Ale Algra ◽  
Gabriël J.E. Rinkel
Keyword(s):  
Intracranial Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
Risk Of Rupture

scholarly journals Unruptured intracranial aneurysms: natural history and management decisions

2004 ◽  
Vol 17 (5) ◽  
pp. 1-6 ◽  
Author(s):  
Leodante B. da Costa ◽  
Thorsteinn Gunnarsson ◽  
M. Christopher Wallace
Keyword(s):  
Neurological Deficit ◽  
Intracranial Aneurysms ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
International Study ◽  
Special Importance ◽  
Surgical Morbidity ◽  
Mortality And Morbidity ◽  
Unruptured Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
Risk Of Rupture

Aneurysmal subarachnoid hemorrhage (SAH) carries a grim prognosis, with high mortality and morbidity rates. The mortality rate in the first 30 days postrupture is estimated to be in the range of 40 to 50%, and almost half of the survivors will be left with a neurological deficit. Unlike patients with aneurysmal SAH, those with unruptured intracranial aneurysms usually experience no neurological deficit, and their treatment is prophylactic, aiming to reduce the risk of future bleeding and its consequences. The risk of rupture therefore assumes special importance when making decisions regarding which patient or aneurysm to treat. In previous reports the risk of bleeding for unruptured aneurysms has been stated as approximately 2% per year. The retrospective part of the International Study of Unruptured Intracranial Aneurysms (ISUIA) reported very low annual bleeding rates (0.05–1%) and high surgical morbidity and mortality rates (8–18%), prompting discussion in which the benefits of prophylactic treatment in the majority of these lesions were questioned. Prospective data from the second part of the ISUIA recently included rupture rates ranging from 0 to 10% per year. The aim of this paper was to review the evidence that is currently available for neurosurgeons to use when making decisions regarding patients who would benefit from treatment of an unruptured intracranial aneurysm.

Postoperative quality of life of patients treated for asymptomatic unruptured intracranial aneurysms

2007 ◽  
Vol 107 (6) ◽  
pp. 1086-1091 ◽  
Author(s):  
Shigeo Yamashiro ◽  
Toru Nishi ◽  
Kazunari Koga ◽  
Tomoaki Goto ◽  
Daisuke Muta ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Intracranial Aneurysms ◽  
Short Form ◽  
Reference Population ◽  
Anxiety And Depression ◽  
Unruptured Intracranial Aneurysms ◽  
Number Of Patients ◽  
Sf 36 ◽  
Risk Of Rupture

Object The aim of this study was to assess the quality of life (QOL) of patients who underwent surgery for asymptomatic unruptured intracranial aneurysms (UIAs). Methods The authors assessed QOL in 149 patients who had undergone microsurgical clipping of asymptomatic UIAs. They surveyed these patients using universal methods such as the 36-Item Short Form Health Survey (SF-36) for health-related QOL and the Hospital Anxiety and Depression Scale for anxiety and depression assessments. Results The patients' mean scores for each of the eight domains of SF-36 were comparable to those of a Japanese reference population. Analysis of data from the average-QOL and low-QOL subgroups showed that the low-QOL group contained a higher number of patients with preexisting heart diseases and restricted activities of daily living. Operative procedures and complications did not affect QOL. Conclusions Because 86% of the patients who underwent surgery manifested a QOL similar to the reference population, the authors suggest that elective surgery for asymptomatic UIAs is a reasonable treatment, especially in patients who are troubled by the risk of rupture. Postoperative decreases in QOL are not invariably attributable to the operation or its associated complications, but may be correlated with other chronic disorders. To select the appropriate treatment for asymptomatic UIAs, neurosurgeons and patients need information on the expected postoperative QOL.

scholarly journals Intracranial Aneurysms: Does Size Really Matter?

2020 ◽  
Vol 1 (4) ◽  
Author(s):  
Kashif Majeed ◽  
Srikanth R Boddu ◽  
Joseph Carnevale ◽  
Elif Ezgi Cenberlitas ◽  
Nicholas Williams ◽  
...  
Keyword(s):  
Intracranial Aneurysms ◽  
International Study ◽  
Surgical Clipping ◽  
Aneurysmal Rupture ◽  
Ruptured Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
Risk Of Rupture ◽  
Brainstem Stroke ◽  
Size Groups ◽  
The Mean

Abstract BACKGROUND To stratify the risk of aneurysmal rupture, size remains the primary criterion as proposed by 2 ISUIA (International Study of Unruptured Intracranial Aneurysms) trials that recommend the observation of ≤7 mm aneurysms because of their low propensity to rupture. These recommendations are controversial, given the severe outcomes following hemorrhage. OBJECTIVE To retrospectively assess whether size correlates with aneurysmal rupture, and to analyze outcomes of endovascular and microsurgical procedures. METHODS All aneurysms presenting between 2016 and 2019 were reviewed. Age, gender, comorbidities, ruptured status, modes of treatment, and their outcomes were noted. Regression analysis was performed to correlate size with rupture. The type of intervention was based on clinical and aneurysmal characteristics and the likelihood of obliteration. RESULTS Of the 668 aneurysms, 116 had ruptured. In size groups 0 to 6 mm,  7 to 12 mm,  13 to 18 mm,  18 to 24 mm, and giant, the ruptured aneurysms were 60.3%, 30.2%, 1.7%, 0.9%, and 6.9%, respectively. The majority (423) were managed endovascularly, of which 84 (19.9%) were ruptured. A total of 97 (14.5%) underwent clipping, of which 31 were ruptured. The mean modified Rankin Scale for both treated groups was zero. One death in each group and a single brainstem stroke in the coiled group were noted. A total of 139 were followed, of which none had ruptured. The mean modified Raymond-Roy classification for endovascular therapy was 1.1, with 380 completely occluded; 15 had a score of 2, and 28 of score 3. CONCLUSION The ruptured aneurysms were mostly smaller than reported previously. Surgical clipping was at equipoise with endovascular treatments. Further studies to correlate aneurysmal characteristics to the risk of rupture are needed.

scholarly journals Rupture immediately after growth of unruptured intracranial aneurysms during follow-up

2019 ◽  
Vol 10 ◽  
pp. 164
Author(s):  
Taro Yanagawa ◽  
Yoichi Harada ◽  
Toru Hatayama ◽  
Takuji Kono
Keyword(s):  
Intracranial Aneurysms ◽  
Internal Carotid ◽  
Artery Aneurysm ◽  
Resonance Imaging ◽  
Middle Cerebral Artery Aneurysm ◽  
Ruptured Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
Risk Of Rupture ◽  
Cerebral Artery Aneurysm

Background: The annual rupture rate of small unruptured intracranial aneurysms (UIAs) <5 mm is generally low; further, small UIAs are often treated conservatively. While the growth of aneurysms during follow-up is associated with a high risk of rupture, the urgency for surgical treatment of asymptomatic enlarged UIAs remains controversial. We experienced two patients in whom UIAs ruptured shortly after asymptomatic growth during follow-up. Case Description: A 1-mm right middle cerebral artery aneurysm was incidentally found in a 63-year-old woman. Preventive surgery was planned because the aneurysm grew rapidly; however, the aneurysm ruptured preoperatively. A 68-year-old woman had a small (4 mm) aneurysm at the left internal carotid-posterior communicating artery. The aneurysm grew rapidly after many years. Several hours after magnetic resonance imaging was performed, she presented to the hospital with loss of consciousness, and a diagnosis of subarachnoid hemorrhage due to the ruptured aneurysm was made. Conclusion: UIAs that rapidly increase during follow-up may be regarded as impending ruptured aneurysms.

scholarly journals Development of an Intravascular Doppler Optical Coherence Tomography Imaging Technique for Neurovascular Applications

2021 ◽  
Author(s):  
Barry Vuong
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Intracranial Aneurysm ◽  
Intracranial Aneurysms ◽  
Fluid Dynamic ◽  
Patient Specific ◽  
Optical Coherence ◽  
Specific Flow ◽  
Arterial Lumen ◽  
Risk Of Rupture

The rupture of an intracranial aneurysm can cause spontaneous subarachnoid hemorrhage and result in sudden death. A large portion of intracranial aneurysms occurs near the center of the head, at the skull base, which poses significant technical challenge to neurosurgeons due to limited accessibility. The utilization of angiography is prominent during the treatment of intracranial aneurysms. However, malapposition of stent or incomplete packing of the intracranial aneurysm can be difficult to assess with angiography, and could lead to severe postoperative complications. As a result, angiography may not be sufficient in determining the risk of rupture as the compensatory mechanisms are known to occur at the microstructural level due to the local hemodynamics in the arterial lumen, as well as in evaluating the intraoperative treatment. In this work, we describe a method for assessing intracranial aneurysm through the evaluation of blood flow within the lumen and morphological structures of the arterial wall with optical coherence tomography (OCT). Sterile intravascular fiber-optic catheters can be introduced in the artery to detect blood flow. Prior to this work, limited investigations of catheter based Doppler OCT (DOCT) were reported. A novel signal processing technique was developed to further reduce the effect of Doppler noise within a catheter based DOCT system. This technique consisted of splitting the interferogram of an OCT signal prior to estimating the Doppler shift. This split spectrum DOCT (ssDOCT) method was evaluated through flow models and porcine models, as well as through the correlation between ssDOCT algorithm and computational fluid dynamic (CFD) models. It was observed that ssDOCT provided improved Doppler artefact suppression over the conventional DOCT technique. ssDOCT also provided the ability to estimate lower velocities within the DOCT image to measure the hemodynamic patterns around stent struts in both the internal carotid and patient specific flow phantoms. An OCT imaging study was also conducted consisting of surgically resected human intracranial aneurysms. Further enhancement of the detection of these key morphological structures was demonstrated by an optical-attenuation imaging variant of OCT. The presented techniques could provide further insights to the cause of intracranial aneurysm rupture and vascular healing mechanisms.

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