Prevalence of intracranial saccular aneurysms in a Japanese community based on a consecutive autopsy series during a 30-year observation period. The Hisayama study

CD68 Antigen and Cerebral Aneurysms: A Case-Control Study

BACKGROUND

 Intracranial aneurysms are more commonly associated with inflammation as a cause of their development, progression, and rupture. Macrophages and other cells can express the CD68 antigen. The aim of this study was to assess the CD68 antigen levels in cerebral aneurysm (CA) patients compared to a control group at a referral center in Iran.

METHODS

 A case-control investigation was undertaken on 88 individuals (44 of whom were cases and 44 were controls). Individuals with CA as the case group consisted of 28 ruptured and 16 unruptured subgroups. Clinical, radiographic, and CD68 levels were evaluated and registered.

RESULTS

 The average age of the participants was 49 years. Males comprised 43.2% of the patients, while 56.8% were females (p = 0.002). There was a statistically significant difference in the CD68 levels between the two groups. There was no significant difference (p = 0.42) between the ruptured and unruptured subgroups (23.66 and 20.47, respectively) in this comparison. No significant correlation was seen between the patients' CD68 and Glasgow Coma Scale (GCS) levels and their aneurysm diameter (p = 0.74 and 0.45, respectively). A link between CD68 levels and age was found, but it was not statistically significant (r = 0.44 and p = 0.002).

CONCLUSIONS

 A possible involvement of CD68 as an inflammatory agent in the development of CAs but not in aneurysm rupture has been suggested. Inflammation and CD68 were positively associated with age. The CD68 antigen should be studied further in population-based cohort studies.

Cerebral Aneurysm Characteristics and Surgical Outcomes: An In-Depth Analysis of 346 Cases Operated Using Microsurgical Clipping

This comprehensive study analyzes 346 surgically treated intracranial aneurysms, emphasizing the importance of understanding risk factors and prevalent characteristics in patients. Intracranial aneurysms, primarily of the saccular or berry type, significantly contribute to nontraumatic subarachnoid hemorrhages and demonstrate a rising incidence due to advances in imaging techniques. The study highlights a gender discrepancy in aneurysm occurrence and a higher prevalence in individuals over 30 years old. The research delves into various aspects, including aneurysm localization, diameter, neck dimensions, and rupture status, with a focus on the anterior communicating artery and middle communicating artery as predominant locations. Significant findings include the prevalence of ruptured aneurysms and the impact of arterial hypertension, atherosclerosis, obesity, and diabetes on aneurysm epidemiology. The study also investigates the occurrence of vasospasm, a significant factor in delayed morbidity and mortality in aneurysmal subarachnoid hemorrhage. The utilization of the Glasgow Outcome Scale and other quantification scales aids in understanding the severity and postoperative outcomes of intracranial aneurysms. Challenges such as the incidence of reopenings and postoperative osteomyelitis are addressed, underlining the need for refined protocols and multidisciplinary approaches in treatment. The study's results contribute to the existing knowledge base on intracranial aneurysms, emphasizing the importance of ongoing research and tailored treatment strategies. The comprehensive nature of this analysis, covering preoperative, intraoperative, and postoperative factors, provides valuable insights into the complex interplay of risk factors and clinical outcomes in patients with intracranial aneurysms.

Risk factors of unruptured intracranial aneurysms instability in the elderly

BACKGROUND

Presently, a consistent strategy for determining the stability of unruptured intracranial aneurysms (UIAs) in elderly patients is lacking, primarily due to the unique characteristics of this demographic. Our objective was to assess the risk factors contributing to aneurysm instability (growth or rupture) within the elderly population.

METHODS

In this study, we compiled data from follow-up patients with UIAs spanning from November 2016 to August 2021. We specifically focused on patients aged ≥ 60 years. Clinical histories were gathered, and morphological parameters of aneurysms were measured. The growth of aneurysms was determined using the computer-assisted semi-automated measurement (CASAM). Growth and rupture rates of UIAs were calculated, and both univariate and multivariate Cox regression analyses were conducted. Additionally, Kaplan-Meier survival curves were plotted.

RESULTS

A total of 184 patients with 210 aneurysms were enrolled in the study. The follow-up period encompasses 506.6 aneurysm-years and 401.4 patient-years. Among all the aneurysms, 23 aneurysms exhibited growth, with an annual aneurysm growth rate of 11.0%, and 1 (4.5%) experienced rupture, resulting in an annual aneurysm rupture rate of 0.21%. Multivariate Cox analysis identified poorly controlled hypertension (P = 0.011) and high-risk aneurysms (including anterior cerebral artery (ACA), anterior communicating artery (AcoA), posterior communicating artery aneurysm (PcoA), posterior circulation (PC) > 4 mm or distal internal carotid artery (ICAd), middle cerebral artery (MCA), and PC > 7 mm) (P = 0.006) as independent risk factors for the development of unstable aneurysms.

CONCLUSIONS

In the elderly, poorly controlled hypertension and high-risk aneurysms emerge as significant risk factors for aneurysm instability. This underscores the importance of rigorous surveillance or timely intervention in patients presenting with these risk factors.

Effectiveness of tuning an artificial intelligence algorithm for cerebral aneurysm diagnosis: a study of 10,000 consecutive cases

Diagnostic image analysis for unruptured cerebral aneurysms using artificial intelligence has a very high sensitivity. However, further improvement is needed because of a relatively high number of false positives. This study aimed to confirm the clinical utility of tuning an artificial intelligence algorithm for cerebral aneurysm diagnosis. We extracted 10,000 magnetic resonance imaging scans of participants who underwent brain screening using the "Brain Dock" system. The sensitivity and false positives/case for aneurysm detection were compared before and after tuning the algorithm. The initial diagnosis included only cases for which feedback to the algorithm was provided. In the primary analysis, the sensitivity of aneurysm diagnosis decreased from 96.5 to 90% and the false positives/case improved from 2.06 to 0.99 after tuning the algorithm (P < 0.001). In the secondary analysis, the sensitivity of aneurysm diagnosis decreased from 98.8 to 94.6% and the false positives/case improved from 1.99 to 1.03 after tuning the algorithm (P < 0.001). The false positives/case reduced without a significant decrease in sensitivity. Using large clinical datasets, we demonstrated that by tuning the algorithm, we could significantly reduce false positives with a minimal decline in sensitivity.

The influence of contralateral circulation on computational fluid dynamics of intracranial arteries: simulated versus measured flow velocities

BACKGROUND

This study aimed to retrospectively evaluate the influence of contralateral anterior circulation on computational fluid dynamics (CFD) of intracranial arteries, by comparing the CFD values of flow velocities in unilateral anterior circulation with the measured values from phase-contrast magnetic resonance angiography (PC-MRA).

METHODS

We analyzed 21 unilateral anterior circulation models without proximal stenosis from 15 patients who performed both time-of-flight MRA (TOF-MRA) and PC-MRA. CFD was performed with the inflow boundary condition of a pulsatile flow of the internal carotid artery (ICA) obtained from PC-MRA. The outflow boundary condition was given as atmospheric pressure. Simulated flow velocities of the middle cerebral artery (MCA) and anterior cerebral artery (ACA) from CFD were compared with the measured values from PC-MRA.

RESULTS

The velocities of MCA were shown to be more accurately simulated on CFD than those of ACA (Spearman correlation coefficient 0.773 and 0.282, respectively). In four models with severe stenosis or occlusion of the contralateral ICA, the CFD values of ACA velocities were significantly lower (< 50%) than those measured with PC-MRA. ACA velocities were relatively accurately simulated in the models including similar diameters of both ACAs.

CONCLUSION

It may be necessary to consider the flow condition of the contralateral anterior circulation in CFD of intracranial arteries, especially in the ACA.

RELEVANCE STATEMENT

Incorporating the flow conditions of the contralateral circulation is of clinical importance for an accurate prediction of a rupture risk in Acom aneurysms as the bidirectional flow and accurate velocity of both ACAs can significantly impact the CFD results.

KEY POINTS

• CFD simulations using unilateral vascular models were relatively accurate for MCA. • Contralateral ICA steno-occlusion resulted in an underestimation of CFD velocity in ACA. • Contralateral flow may need to be considered in CFD simulations of ACA.

Will improved neuroradiology facilities debunk the reported rarity of intracranial aneurysms in Sub-Saharan Africa?

Background:

Intracranial aneurysms (IAN) are rare in the Sub-Saharan Africa unlike other parts of the world. The debate is whether the low frequency might be apparent because of the scarcity of advanced neuroimaging services, or real. This study investigated if improved imaging facilities would debunk the rarity of IAN in our subregion.

Methods:

This is a retrospective cohort study of prospectively recorded data of patients with subarachnoid hemorrhage (SAH) and IAN managed over 19 years (2003–2021), at the study center with a catchment population of over 47 million. The center witnessed progressive improvements in neuroimaging facilities: 2-Slice, 8-slice, and 64-slice computed tomography (CT) and 0.35T, 1.5T magnetic resonance imaging (MRI) during the period.

Results:

There were 241 cases of SAH, but only 166 aneurysms were confirmed in 158 patients. Between 2003 and 2008, only 27 IAN patients (4.5 IAN/year) were diagnosed. After introduction of CT angiography/magnetic resonance angiography MRA using 8-slice CT/0.35T magnetic resonance imaging (MRI), between 2009 and 2014, the frequency of IAN increased to 8/year. Between 2015 and 2018 after installation of a 64-slice CT in 2014, the IAN remained the same (8/year). MRI 1.5T was added in 2018, the frequency doubled to 17 cases/year. The females were more (67.7%), the mean age was 46.3 years, but peak incidence was the sixth decade. Internal carotid artery aneurysms including posterior communicating artery were the most common (43%) followed by ACA with anterior communicating artery (24%) and middle cerebral artery (20%). Multiple aneurysms were seen in ten patients.

Conclusion:

Improved neuroimaging between 2003 and 2021 did not debunk the rarity of IAN in our region.

An Analysis of Landmark Articles Regarding Aneurysms of the Middle Cerebral Artery

OBJECTIVE

Aneurysms located on the middle cerebral artery (MCA) range from 22% to 31.5% in prevalence of all aneurysms in the anterior cerebral circulation. This bibliometric analysis summarizes the most cited articles on MCA aneurysms and highlights the landmark publications that contributed to evidence-based practice.

METHODS

In the execution of this bibliometric-based review article, the Scopus database was used to perform a title-specific, keyword-based search for all publications until August 2022. The keyword "(middle cerebral artery OR MCA) AND aneurysm" was used. Our results were arranged in descending order based on the citation count of the article. The 100 most cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact per Paper, and Hirsch index.

RESULTS

The keyword-based search showed that 1206 articles on MCA aneurysms were published up to August 2022. The top 100 articles were published between 1940 and 2019. The top 100 most cited articles collected a total of 6232 citations with an average of 62.3 citations per article. The rate of self-citations accounted for an average of 5.75% of the total number of citations.

CONCLUSIONS

The bibliometric analysis provides a quantitative overview of how medical literature and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in research regarding MCA aneurysms by finding the top 100 most cited articles.

The clinical significance of peripheral blood cell ratios in patients with intracranial aneurysm

Background and objective

Inflammation is an important factor in the development of aneurysm, and has been identified as a key characteristic predictive of rupture of intracranial aneurysm (IA). However, the role of inflammatory peripheral blood cell ratios in patients with IA has not been well delineated.

Methods

A total of 1,209 patients, including 1,001 with unruptured IA and 208 with ruptured IA, were enrolled in this study. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), platelet-to-neutrophil ratio (PNR), and platelet-to-white-blood-cell ratio (PWR) were compared between ruptured and unruptured IA.

Results

Compared with the ruptured IA group, the unruptured IA group had higher PNR {median, 65.96 [interquartile range (IQR) 48.95-85.05] vs. 37.78 (IQR, 23.17-54.05); p < 0.001} and PWR [median, 36.89 (IQR 29.38-44.56) vs. 22.39 (IQR, 16.72-29.29); p < 0.001]. In multivariate analysis, PNR and PWR were independently associated with ruptured IA (p = 0.001 and p < 0.001, respectively). Unruptured IA subgroup analyses according to the PHASES scores showed that a higher PHASES score was associated with significantly higher NLR and erythrocyte sedimentation rate (p < 0.001 and p = 0.025) and lower PNR and PWR (p < 0.001 and p = 0.007).

Conclusions

We demonstrated that lower PNR and PWR levels are associated with ruptured IA and a higher PHASES score. Unlike many other inflammatory markers and bioassays, peripheral blood cell ratios are inexpensive and readily available biomarkers that may be useful for risk stratification in patients with cerebral aneurysm. However, a long-term prospective study is needed to clarify this matter.

Long-term outcomes, including the survival rate and period to death, in patients over 80 years old after ruptured cerebral aneurysm clipping

OBJECTIVE

This study aimed to identify the long-term outcomes, including the survival rate, period to death, causes of death, and predictors of poor outcomes, in patients aged over 80 years who underwent surgical clipping for a ruptured anterior circulation aneurysm.

MATERIALS AND METHODS

In this retrospective observational study, the medical records of patients from April 1, 1994, to June 30, 2019, were evaluated. All patients underwent surgical clipping within 72 h of subarachnoid hemorrhage (SAH) onset. Information on the patient, SAH, and outcomes were collected.

RESULTS

The mean hospitalization and long-term follow-up periods for all patients were 54.5 days and 53.3 months, respectively. The period to death was significantly shorter in patients with modified Rankin scale (mRS) of 4-5 than for those with an mRS of 0-3 at discharge (p=0.001). The Kaplan-Meier method using the log-rank test demonstrated that patients with an mRS of 4-5 at discharge had a significantly lower survival rate compared to those with an mRS of 0-3 at discharge (p<0.05). Univariate analysis revealed that the proportion of patients with Hunt and Hess grade and presence of surgical complications were significantly larger in the group with an mRS of 4-5 than in that with an mRS of 0-3 at discharge (p=0.0013 and 0.011, respectively). Multivariate analysis demonstrated that presence of surgical complications was the only independent predictor of poor outcomes (p=0.043, odds ratio [OR] 7.937, 95% confidence interval [CI] 1.061-59.38). The Kaplan-Meier method using the log-rank test demonstrated that patients with surgical complications had a significantly lower survival rate compared to those with no surgical complications (p<0.05).

CONCLUSIONS

Especially in patients aged over 80 years, those with H-H grade 2 and a good clinical condition can be candidates for surgical clipping, whereas avoiding surgical complications is essential for achieving good outcomes.

Variations of perforating arteries of anterior communicating artery in cases with anterior communicating artery aneurysms: a cadaveric anatomical study

PURPOSE

In terms of postoperative morbidity and mortality, preservation of the perforating arteries branching from the anterior communicating artery (ACoA) during clipping is particularly imperative in patients with ACoA aneurysm. In the present study, we aimed to investigate whether perforating arteries originated from ACoA were pushed away in a different location in patients with ACoA aneurysm. Furthermore, if they did so, we aimed to identify the direction in which they were dislocated and how the perforating arteries could be preserved during clipping.

METHODS

Herein, we categorized 40 brains obtained from cadavers into two groups. The first (n = 26) and second (n = 14) groups included cases without and with ACoA aneurysms, respectively. After completing the preparation procedure, the brains were dissected using surgical microscope and the relevant anatomical region was examined and photographed. Finally, statistical analyses were performed on the data and the results were documented.

RESULTS

In the aneurysms with posterior and superior projections, the perforators appeared to be pushed away inferiorly and were frequently noted at the anteroinferior part of the aneurysm neck. Most of the cases, where one of the A1s was larger at one side, the perforating arteries arose from the larger A1 side.

CONCLUSION

The mortality and morbidity associated with damage to the perforators can be reduced by approaching the patient from the dominant A1 side and pursuing the perforators primarily at the anteroinferior part of the aneurysm neck in the aneurysms with superior and posterior projections.

Prevalence of cerebral aneurysms in autopsy studies: a review of the literature

Cerebral aneurysms (CAs) are one of the most important causes of stroke, but details of their prevalence remain under-researched. Autopsy data for CAs were reviewed using standard search engines. Based on previously published autopsy and clinical studies, the prevalence of CAs with respect to age, gender, and aneurysm site, size, and multiplicity was investigated, and the natural course of CA prevalence was estimated. In autopsy studies, the prevalence of CAs across all age groups was 0.3-4.0% for unruptured cerebral aneurysms (UCAs) and 1.3-7.6% for CAs including UCAs and ruptured cerebral aneurysms (RCAs). Patients with UCAs were generally older than those with RCAs. Middle cerebral artery aneurysms were more predominant in autopsy studies than in clinical studies. UCAs tended to be smaller than RCAs, and minute UCAs (< 2 mm), diagnosed microscopically at autopsy and thought to be in the very early stages of formation, were present in 10-20% of the general population. Taking into consideration the clinical data for UCAs and RCAs, 10% of minute UCAs enlarge to major UCAs (≥ 2 mm) detectable by conventional imaging techniques, and 10% of major UCAs eventually rupture within 10 years. The high prevalence of UCAs and RCAs in the elderly and women can be attributed to the more frequent occurrence of minute UCAs in these populations. Minute UCAs occur at a high rate, but only a few enlarge to become major UCAs and rupture. Further advances in diagnostic technology are essential for revealing the true natural course of CA prevalence.

Intracranial hemorrhage associated with direct oral anticoagulant after clipping for an unruptured cerebral aneurysm: A report of two cases

Background:

Two cases of patients who developed intracranial hemorrhage associated with direct oral anticoagulant (DOAC) use after clipping of an unruptured cerebral aneurysm (uAN) are presented. These cases will help neurosurgeons assess the risks of patients with atrial fibrillation or deep venous thrombosis receiving DOACs who require craniotomy.

Case Description:

Case 1 was a 65-year-old man on apixaban 10 mg/day who underwent clipping for a left middle cerebral artery uAN. Apixaban was discontinued 72 h before surgery. During surgery, a thin and pial artery bled slightly at 1 point of the frontal lobe, and hemostasis was easily achieved. Computed tomography (CT) 19 h after surgery showed no evidence of intracranial hemorrhage. He was treated with a heparin-apixaban bridge from 29 h to 41 h after surgery. CT showed a left subarachnoid hematoma 24 h later. Case 2 was a 73-year-old woman on dabigatran 110 mg/day who underwent clipping for a right MCA uAN. Dabigatran was discontinued 48 h before surgery. During surgery, a thin and pial artery bled slightly at 2 points of the temporal lobe, and hemostasis was easily achieved. CT 19 h after surgery showed no evidence of intracranial hemorrhage. Dabigatran (110 mg/day) was restarted 29 h after surgery. CT then showed a right subarachnoid hematoma 94 h later, and dabigatran was discontinued, and it was then restarted 38 h later. However, 31 h later, CT showed an additional slight subarachnoid hemorrhage. Finally, she developed a right chronic subdural hematoma.

Conclusion:

In patients undergoing neurosurgical procedures, discontinuation of DOACs should be individualized based on neurosurgical bleeding risk and patient renal function. Restarting of DOACs could be considered after at least 48 h when hemostasis has been achieved. Bridging of DOACs cannot be recommended.

Unruptured cerebral aneurysms in elderly patients: key challenges and management

Unruptured cerebral aneurysms are increasingly identified in elderly patients as the global life expectancy continues to rise and non-invasive vascular imaging becomes more prevalent. The optimal management of unruptured aneurysms in elderly patients remains controversial. Variability in life expectancy, comorbidities and rupture risk coupled with heterogenous endovascular and surgical treatments contribute to a paucity of clear guidelines, and current management is highly individualized. Elderly patients present unique considerations including frailty, cognitive dysfunction, vasculopathy, reduced life expectancy and overall worse prognosis in case of rupture which shape the risks and likelihood of success of endovascular and microsurgical treatment. In this review, we provide a comprehensive overview of unruptured cerebral aneurysms in the elderly, with a particular focus on the natural history, key challenges associated with advanced age, management and future innovations to further refine treatment.Key MessagesThe management of unruptured cerebral aneurysms in elderly patients remains controversial.Key challenges including frailty, cognitive dysfunction, reduced life expectancy, vasculopathy and poor prognosis with aneurysm rupture add complexity to endovascular and surgical decision making not encountered with younger demographics.A thorough understanding of available treatment options, likelihood of treatment success and associated risks weighed against the risk of aneurysm rupture informs patient discussion and management.

Sensitivity of the Unruptured Intracranial Aneurysm Treatment Score (UIATS) in the Elderly: Retrospective Analysis of Ruptured Aneurysms

BACKGROUND/PURPOSE

The prevalence of intracranial aneurysms, as well as the incidence of subarachnoid hemorrhage (SAH), increase with age, and the elderly have poor outcomes after SAH. Age is a key factor in the unruptured intracranial aneurysm treatment score (UIATS),but the sensitivity of the UIATS model in detecting risk of SAH among the elderly is unknown.

METHODS

We retrospectively analyzed 153 consecutive cases of ruptured aneurysms between 2012 and 2018. We used Fisher's exact test, analysis of variance, and multivariate logistic regression to compare outcomes between those >65 years of age and those younger. We then applied the UIATS model and evaluated the sensitivity of the model as a predictor of SAH in the elderly compared with younger patients.

RESULTS

Elderly patients made up 32% (n = 49 of 153) of our cohort. They had significantly higher in-hospital mortality (19 of 49, 39%) than younger patients (14 of 104, 13%) (P < 0.01). In a multivariate logistic regression, controlling for Hunt-Hess grade and comorbidities, age >65 years remained a significant predictor of unfavorable outcome at discharge (P = 0.03). The UIATS model had low sensitivity in the elderly compared with younger patients: 63% (59 of 136) of younger patients would have been recommended aneurysm repair had their aneurysm been detected unruptured, compared with only 12% (5 of 42) of elderly patients >65 years (P < 0.01).

CONCLUSIONS

Elderly patients >65 years in age have far worse outcomes after SAH. The sensitivity of the UIATS model for detecting those at risk of SAH was significantly lower in elderly patients. The UIATS model may lead to undertreatment of elderly patients at risk of SAH.

Clinical and Morphological Characteristics of Ruptured Small (<5 mm) Posterior Communicating Artery Aneurysms

Context:

Small intracranial aneurysms (IAs) are considered to have a low risk of rupture; however, in clinical practice, we often encounter patients with subarachnoid hemorrhage (SAH) due to rupture of small IAs.

Aims:

This study aims to clarify the clinical and morphological characteristics of ruptured small IA, focusing on posterior communicating artery (PCoA) aneurysms as a prone site.

Settings and Design:

We retrospectively reviewed 102 consecutive patients with SAH due to ruptured PCoA aneurysm who underwent microsurgical or endovascular aneurysm repair between April 2013 and March 2018.

Subjects and Methods:

All PCoA aneurysms were diagnosed using three-dimensional rotation angiography or three-dimensional computed tomography angiography. Information regarding the following clinical characteristics was collected: age, sex, past medical history, current smoking, antithrombotic therapy, multiplicity, hydrocephalus, intracerebral hemorrhage, intraventricular hemorrhage, and World Federation of Neurosurgical Societies (WFNS) Grade on admission.

Statistical Analysis Used:

We analyzed factors of ruptured small IA, focusing on PCoA aneurysms using univariate and multivariate regression analyses.

Results:

Univariate and multivariate analyses revealed that low aspect ratio (AR) (odds ratio [OR] = 0.33, P = 0.01) and nonfetal type of PCoA (OR = 0.31, P = 0.02) might be independent characteristics of ruptured small PCoA aneurysms. However, age, sex, past medical history, WFNS grade, and treatment outcome were not different between the small and nonsmall PCoA aneurysms. The aneurysm size was not associated to the selection of treatment, proportion of complications, and treatment outcome.

Conclusions:

In cases of ruptured PCoA aneurysms, low AR and nonfetal type of PCoA might be associated with rupture of small aneurysms.

Prevalence of Unruptured Intracranial Aneurysms: A Single Center Experience Using 3T Brain MR Angiography

Purpose

The purpose of this study was to evaluate the prevalence and risk factors of unruptured intracranial aneurysms (UIAs), which can help establish guidelines of treatment for asymptomatic Korean adults using 3T magnetic resonance angiography (MRA).

Materials and Methods

Our Institutional Review Board approved this retrospective study, and informed consent was waived. All patients consisted of healthy individuals who underwent brain MRA using 3T magnetic resonance imaging between January 2011 and December 2012 as part of a routine health examination. Patient data and follow-up results were obtained from medical records.

Results

A total of 2,118 individuals (mean age=53.9±9.6 years, male:female=1,188:930) who had undergone brain MRA were enrolled in the study. UIAs were found in 80 patients with 105 UIAs (3.77%). Female predominance (55% in UIA vs. 43.47% in non-UIA, P=0.0416) and hypertension were more common in the UIA group (43.75% vs. 28.8%, P=0.004, respectively). The mean size of the aneurysms was 3.10±1.62 mm, and they were all saccular in shape and asymptomatic. The UIAs were most common in the internal carotid artery (59.1%), internal carotid-posterior communicating artery (15.2%), middle cerebral artery (9.5%), anterior communicating artery (8.6%), anterior cerebral artery (4.8%), and vertebral artery (2.9%). Twenty-eight of 80 patients (35%) had multiple aneurysms. The incidence of UIAs increased significantly with age (P=0.014).

Conclusion

In single center experience, we demonstrated the characteristics and prevalence of UIAs in asymptomatic adults, which may help establish guidelines or therapeutic standards for UIAs.

Endovascular coil embolization for unruptured intracranial aneurysms in patients over 80 years of age

Objective

As the average life span in modern society continues to increase, much interest is focused on high-risk procedures in elderly patients, including major surgical operations. We investigated the results of endovascular coiling of unruptured intracranial aneurysms (UIA) in patients over 80 years of age.

Methods

We retrospectively analyzed 39 patients aged over 80 years who underwent coil embolization for UIA between April 2007 and April 2019 at our hospital.

Results

Complete occlusion on digital subtraction angiography (DSA) immediately after surgery was performed in 44 (84.6%) of 52 cases of cerebral aneurysms. Four patients (7.7%) had residual aneurysmal necks, and four (7.7%) had contrast flow in the aneurysmal sac. Follow-up magnetic resonance angiography (mean: 8.2 months) was performed in 37 aneurysms in 24 patients. There was evidence of blood flow in the neck in seven cases (18.9%) and aneurysm in two cases (5.4%). Follow-up DSA (mean: 20.5 months) was performed in 14 aneurysms in 11 patients, and 11 aneurysms (78.6%) had complete occlusion, 1 aneurysm (7.1%) had an aneurysmal neck, and 2 aneurysms (14.3%) had contrast filling into the aneurysmal sac. Coil embolization procedure-related complications occurred in 3 patients (7.7%). Cerebral infarction occurred in 1 (2.6%), arterial dissection in 1 (2.6%), and hypoesthesia in 1 (2.6%).

Conclusions

Active treatment of UIA in elderly patients over 80 years of age through endovascular coil embolization can be considered.

[Setting Method of the Optimal Slab of Brain MRA for Detective Unruptured Cerebral Aneurysm]

Generally, the imaging range of the brain magnetic resonance angiography (MRA) is determined in the subjectivity by the operator used by the plan image that a blood vessel is not depicted. However, a necessary blood vessel may not be often depicted by an error of the setting of the imaging area. Therefore, optimal slab angle, thickness, distance, and image contrast for depiction of the unruptured cerebral aneurysm were examined. The brain MRA of 14 subjects was imaged in a wide area parallel to an orbitomeatal line (OM) line. The line which linked the arteria vertebral (the first cervical vertebrae curved section) to anterior cerebral artery (A3) was determined with an optimal slab base line, and the angle with the OM line was evaluated. Moreover, slavic range including the unruptured aneurysm was calculated. In addition, the distance from the inferior margin of pons to the slavic bottom end was measured. Furthermore, the cerebrovascular contrast by the slave angle was compared. As a result, the slave setting of the range was recommended in brain-MRA as an angle was 34.3 degrees, and the thickness was 56.4 mm, and, as the distance from the inferior margin of pons was 27.6 mm. The cerebrovascular contrast of the optimal slab base line angle did not have a significant difference for an OM line.

Vasa vasorum formation is associated with rupture of intracranial aneurysms

OBJECTIVE

Subarachnoid hemorrhage (SAH) has a poor outcome despite modern advancements in medical care. The development of a novel therapeutic strategy to prevent rupture of intracranial aneurysms (IAs) or a novel diagnostic marker to predict rupture-prone lesions is thus mandatory. Therefore, in the present study, the authors established a rat model in which IAs spontaneously rupture and examined this model to clarify histopathological features associated with rupture of lesions.

METHODS

Female Sprague Dawley rats were subjected to bilateral ovariectomy; the ligation of the left common carotid, the right external carotid, and the right pterygopalatine arteries; induced systemic hypertension; and the administration of a lysyl oxidase inhibitor.

RESULTS

Aneurysmal SAH occurred in one-third of manipulated animals and the locations of ruptured IAs were exclusively at a posterior or anterior communicating artery (PCoA/ACoA). Histopathological examination using ruptured IAs, rupture-prone IAs induced at a PCoA or ACoA, and IAs induced at an anterior cerebral artery-olfactory artery bifurcation that never ruptured revealed the formation of vasa vasorum as an event associated with rupture of IAs.

CONCLUSIONS

The authors propose the contribution of a structural change in an adventitia, i.e., vasa vasorum formation, to the rupture of IAs. Findings from this study provide important insights about the pathogenesis of IAs.

Evaluation of a modular in vitro neurovascular procedure simulation for intracranial aneurysm embolization

BACKGROUND

Rapid development in endovascular aneurysm therapy continuously drives demand for suitable neurointerventional training opportunities.

OBJECTIVE

To investigate the value of an integrated modular neurovascular training environment for aneurysm embolization using additively manufactured vascular models.

METHODS

A large portfolio of 30 patient-specific aneurysm models derived from different treatment settings (eg, coiling, flow diversion, flow disruption) was fabricated using additive manufacturing. Models were integrated into a customizable neurointerventional simulator with interchangeable intracranial and cervical vessel segments and physiological circuit conditions ('HANNES'; Hamburg ANatomic Neurointerventional Endovascular Simulator). Multiple training courses were performed and participant feedback was obtained using a questionnaire.

RESULTS

Training for aneurysm embolization could be reliably performed using HANNES. Case-specific clinical difficulties, such as difficult aneurysm access or coil dislocation, could be reproduced. During a training session, models could be easily exchanged owing to standardized connectors in order to switch to a different treatment situation or to change from 'treated' back to 'untreated' condition. Among 23 participants evaluating hands-on courses using a five-point scale from 1 (strongly agree) to 5 (strongly disagree), HANNES was mostly rated as 'highly suitable for practicing aneurysm coil embolization' (1.78±0.79).

CONCLUSION

HANNES offers a wide variability and flexibility for case-specific hands-on training of intracranial aneurysm treatment, providing equal training conditions for each situation. The high degree of standardization offered may be valuable for analysis of device behavior or assessment of physician skills. Moreover, it has the ability to reduce the need for animal experiments.

Small Aneurysms Should Be Clipped?

Background:

Cerebral aneurysm prevalence may vary from 0.4% to 10%. The decision to treat or not incidental aneurysms remains controversial, especially when the lesions are small (<5 mm). Many recent publications are demonstrating that these lesions often bleed.

Methods:

We reviewed admitted patients with angiographic studies submitted to intracranial aneurysm surgical treatment from April 2012 to July 2013 in the Neurosurgery Department of São Paulo Medical School University (15 months), to define the rate and risk of bleeding. In addition, we proceeded literature review with collected 357 papers (past 5 years) which were selected 50 that were focused on our research. Clinical patients’ status at the time of discharge was evaluated with the modified Rankin scale.

Results:

A series of 118 cases of surgically clipped aneurysms was analyzed: 73.7% woman; Ruptured (61 cases, 51%); middle cerebral artery (51 cases, 43%) was the more common aneurysm. Small size (<5 mm) was 25 cases (21%); that 2 died (16%), 3 (25%) with severe disability,restricted to bed and dependent on nursing care; blood pressure was the main risk factors (56%); and an aneurysm <2 mm (100%) was ruptured.

Conclusion:

The number of small aneurysms in our series was significant (25 cases, 21%), and its rate of bleeding was high (25 cases, 48%), resulting in death and disability in a significant number of cases. Our tendency is for surgical treatment when it is associated with risk factors.

Influence of aging-induced flow waveform variation on hemodynamics in aneurysms present at the internal carotid artery: A computational model-based study

The variation of blood flow waveform in the internal carotid artery (ICA) with age is a well-documented hemodynamic phenomenon, but little is known about how such variation affects the characteristics of blood flow in aneurysms present in the region. In the study, hemodynamic simulations were conducted for 26 ICA aneurysms, with flow waveforms measured in the ICAs of young and older adults being used respectively to set the inflow boundary conditions. Obtained results showed that replacing the young-adult flow waveform with the older-adult one led to little changes (<10%) in simulated time-averaged wall shear stress (WSS), transient maximum WSS, relative residence time and trans-aneurysm pressure loss coefficient, but resulted in a marked increase (32.36 ± 17.24%) in oscillatory shear index (OSI). Frequency-domain wave analysis revealed that the progressive enhancement of low-frequency harmonics dominated the observed flow waveform variation with age and was a major factor contributing to the increase in OSI. Cross-sectional comparisons among the aneurysms further revealed that the degree of increase in OSI correlated positively with some specific morphological features of aneurysm, such as aspect ratio and size ratio. In summary, the study demonstrates that the variation in flow waveform with age augments the oscillation of WSS in ICA aneurysms, which underlies the importance of setting patient-specific boundary conditions in hemodynamic studies on cerebral aneurysms, especially those involving long-term patient follow-up or cross-sectional comparison among patients of different ages.

Detection rates and sites of unruptured intracranial aneurysms according to sex and age: an analysis of MR angiography-based brain examinations of 4070 healthy Japanese adults

OBJECTIVIE

The purpose of this study was to evaluate the detection rate and occurrence site according to patient sex and age of unruptured intracranial aneurysms detected through MRI and MR angiography (MRA).

METHODS

A total of 4070 healthy adults 22 years or older (mean age [± SD] 50.6 ± 11.0 years; 41.9% women) who underwent a brain examination known as “Brain Dock” in the central Tokyo area between April 2014 and March 2015 were checked for unruptured saccular aneurysm using 3-T MRI/MRA. The following types of cases were excluded: 1) protrusions with a maximum diameter < 2 mm at locations other than arterial bifurcations, 2) conical protrusions at arterial bifurcations with a diameter < 3 mm, and 3) cases of suspected aneurysms with unclear imaging of the involved artery. When an aneurysm was definitively diagnosed, the case was included in the aneurysm group. The authors also investigated the relationship between aneurysm occurrence and risk factors (age, sex, smoking history, hypertension, diabetes, and hyperlipidemia).

RESULTS

One hundred eighty-eight aneurysms were identified in 176 individuals (detection rate 4.32%), with the detection rate for women being significantly higher (6.2% vs 3.0%, p < 0.001). The average age in the aneurysm group was significantly higher than in the patients in whom aneurysms were not detected (53.0 ± 11.1 vs 50.5 ± 11.0 years). The detection rate tended to increase with age. The detection rates were 3.6% for people in their 30s, 3.5% for those in their 40s, 4.1% for those in their 50s, 6.9% for those in their 60s, and 6.8% for those in their 70s. Excluding persons in their 20s and 80s—age groups in which no aneurysms were discovered—the detection rate in women was higher in all age ranges. Of the individuals with aneurysms, 12 (6.81%) had multiple cerebral aneurysms; no sex difference was observed with respect to the prevalence of multiple aneurysms. Regarding aneurysm size, 2.0–2.9 mm was the most common size range, with 87 occurrences (46.3%), followed by 3.0–3.9 mm (67 [35.6%]) and 4.0–4.9 mm (20 [10.6%]). The largest aneurysm was 13 mm. Regarding location, the internal carotid artery (ICA) was the most common aneurysm site, with 148 (78.7%) occurrences. Within the ICA, C1 was the site of 46 aneurysms (24.5%); C2, 57 (30.3%); and C3, 29 (15.4%). The aneurysm detection rates for C2, C3, and C4 were 2.23%, 1.23%, and 0.64%, respectively, for women and 0.68%, 0.34%, and 0.21%, respectively, for men; ICA aneurysms were significantly more common in women than in men (5.27% vs 2.20%, p < 0.001). Multivariate logistic regression analysis revealed that age (p < 0.001, OR 1.03, 95% CI 1.01–1.04), female sex (p < 0.001, OR 2.28, 95% CI 1.64–3.16), and smoking history (p = 0.011, OR 1.52, 95% CI 1.10–2.11) were significant risk factors for aneurysm occurrence.

CONCLUSIONS

In this study, both female sex and older age were independently associated with an increased aneurysm detection rate. Aneurysms were most common in the ICA, and the frequency of aneurysms in ICA sites was markedly higher in women.

Safety of antithrombotic therapy for patients with acute ischemic stroke harboring unruptured intracranial aneurysm

Background The safety of antithrombotic therapy for patients with acute ischemic stroke harboring unruptured intracranial aneurysms remains unclear. Aims This study was performed to determine whether treatment with antiplatelets, anticoagulants, or intravenous thrombolytic agents is safe for patients with acute ischemic stroke and unruptured intracranial aneurysms. Methods Among 9149 patients with acute ischemic stroke enrolled in the Fukuoka Stroke Registry from June 2007 to December 2014, 8857 patients with data on cerebrovascular imaging and three-month outcomes were included in this study. The frequency of adverse events, including intracranial hemorrhage, symptomatic intracranial hemorrhage, and in-hospital mortality, was compared between patients with and without unruptured intracranial aneurysms. The risk of a poor functional outcome (modified Rankin scale score of ≥3) at three months after stroke onset was estimated after adjusting for confounding factors by logistic regression analysis. Results Unruptured intracranial aneurysms were identified in 412 (4.7%) patients, and the mean diameter was 4.1 ± 3.2 mm. There was no significant difference in the frequency of any adverse events between patients with and without unruptured intracranial aneurysms among the overall patients or patients receiving antiplatelets, anticoagulants, or intravenous thrombolytic agents. The odds ratios of a poor functional outcome were not significantly higher in the presence of unruptured intracranial aneurysms, even in patients undergoing antiplatelet therapy, anticoagulation therapy, or intravenous thrombolysis. Conclusions These findings suggest that unruptured intracranial aneurysms are not associated with increased risks of adverse events or poor functional outcomes even after antithrombotic therapy for acute ischemic stroke. However, accumulation of cases is required to verify these findings.

Should we still consider clips for basilar apex aneurysms? A critical appraisal of the literature

Background:

Basilar apex aneurysms constitute 5–8% of all intracranial aneurysms, and their treatment remains challenging for both microsurgical and endovascular approaches. The perceived drawback of the microsurgical approach is its invasiveness leading to increased surgical morbidity. However, many high-volume centers have shown excellent clinical results with better occlusion rates compared to endovascular treatment. With endovascular therapy taking a larger role in the management of cerebral aneurysms, the future role of microsurgery for basilar apex aneurysm treatment is unclear.

Methods:

We performed a literature search to review the microsurgical and endovascular outcomes for basilar apex aneurysms.

Results:

Many studies have examined the efficacy of microsurgical and endovascular treatment for intracranial aneurysms, including large randomized trials such as ISAT and BRAT, prospective observational series such as ISUIA, and many single-center retrospective reviews. The recruitment number for posterior circulation aneurysms, specifically for basilar apex aneurysms, was limited in most prospective trials, thus failing to offer clear guidance on basilar apex aneurysm treatment. Recent single-center series report good clinical outcomes between 57–92% for surgical series and 73–96% in endovascular series. The durability of aneurysm occlusion remains superior in surgical cases. The techniques and devices in endovascular treatment have improved treatment aneurysm occlusion rates but more follow-up is needed to confirm long-term durability.

Conclusions:

Both microsurgical and endovascular approaches should be complementing each other to treat basilar apex aneurysms. Although endovascular therapy has taken a larger role in the treatment of basilar apex aneurysms, many indications still exist for the use of microsurgery. Advancements in microsurgical techniques and good case selection will allow for acceptably low morbidity after surgical treatment while maintaining its superior durability.

Is there an association between flow diverter fish mouthing and delayed-type hypersensitivity to metals?-a case-control study

PURPOSE

Flow diverters are increasingly used in the treatment of complex and giant intracranial aneurysms. However, they are associated with complications like late aneurysmal rupture. Additionally, flow diverters show focal structural decrease in luminal diameter without any intimal hyperplasia. This resembles a "fish mouth" when viewed en face. In this pilot study, we tested the hypothesis of a possible association between flow diverter fish-mouthing and delayed-type hypersensitivity to its metal constituents.

METHODS

We retrospectively reviewed patient records from our center between May 2010 and November 2015. A total of nine patients had flow diverter fish mouthing. A control group of 25 patients was selected. All study participants underwent prospective patch test to detect hypersensitivity to flow diverter metal constituents. Analysis was performed using logistic regression analysis and Wilcoxon sign rank sum test. Univariate and multivariate analyses were performed to test variables to predict flow diverter fish mouthing.

RESULTS

The association between flow diverter fish mouthing and positive patch test was not statistically significant. In multivariate analysis, history of allergy and maximum aneurysm size category was associated with flow diverter fish mouthing. This was further confirmed on Wilcoxon sign rank sum test.

CONCLUSION

The study showed statistically significant association between flow diverter fish mouthing and history of contact allergy and a small aneurysmal size. Further large-scale studies are needed to detect a statistically significant association between flow diverter fish mouthing and patch test. We recommend early and more frequent follow-up imaging in patients with contact allergy to detect flow diverter fish mouthing and its subsequent evolution.

Optic neuropathy after anterior communicating artery aneurysm clipping: 3 cases and techniques to address a correctable pitfall

Brain shifts following microsurgical clip ligation of anterior communicating artery (ACoA) aneurysms can lead to mechanical compression of the optic nerve by the clip. Recognition of this condition and early repositioning of clips can lead to reversal of vision loss. The authors identified 3 patients with an afferent pupillary defect following microsurgical clipping of ACoA aneurysms. Different treatment options were used for each patient. All patients underwent reexploration, and the aneurysm clips were repositioned to prevent clip-related compression of the optic nerve. Near-complete restoration of vision was achieved at the last clinic follow-up visit in all 3 patients. Clip ligation of ACoA aneurysms has the potential to cause clip-related compression of the optic nerve. Postoperative visual examination is of utmost importance, and if any changes are discovered, reexploration should be considered as repositioning of the clips may lead to resolution of visual deterioration.

Collagen Type I Alpha 2 (COL1A2) Polymorphism Contributes to Intracranial Aneurysm Susceptibility: A Meta-Analysis

Background

COL1A2, which encodes collagen type I alpha2, has long been suggested to be a potential positional and functional candidate gene for intracranial aneurysm. We performed a meta-analysis to assess the association between COL1A2 rs42524 polymorphism and the risk of intracranial aneurysm.

Material/Methods

We conducted a systematic search for relevant literature from the following databases up to 22 July 2016: PubMed, Embase, Web of Science, and China National Knowledge Infrastructure. The strength of association between gene and disease was estimated using odds ratios (ORs) with 95% confidence intervals (CIs) under 5 genetic models.

Results

A total of 6 qualified studies were enrolled in this meta-analysis. Pooling results indicated a significant association between COL1A2 rs42524 polymorphism and intracranial aneurysm risk under 4 genetic models (C vs. G: OR=1.74, 95%CI=1.34–2.26; GC vs. GG: OR=1.81, 95%CI=1.37–2.41; CC+GC vs. GG: OR=1.74, 95%CI=1.28–2.36; CC vs. GC+GG: OR=1.76, 95%CI=1.02–3.04). This association was still robust when stratified by ethnicity, intracranial aneurysm type, or Hardy-Weinberg Equilibrium, which was stronger in Asian than in Caucasians. No publication bias was observed.

Conclusions

This meta-analysis suggests COL1A2 rs42524 is a significant risk factor for IA susceptibility, with an especially strong effect in Asian people. Further larger-scale epidemiological studies among different ethnicities are warranted to confirm our findings.

Evaluation of Endovascular Embolization of Cerebral Aneurysms by Hydrogel Coils

BACKGROUND

Hydrogel coils were created to improve the chances of an effective endovascular treatment of cerebral aneurysms. Achieving a high packing density of coils in the lumen of aneurysms can decrease the risk of recurrence. The aim of the present study is to report our initial experience on the effectiveness and safety of endovascular treatment of intracranial aneurysms with the use hydrogel coils.

MATERIAL/METHODS

Sixty patients (age: 28-72 years) (45 women, 15 men) were treated. In 18 patients (30%), subarachnoid hemorrhage was present. Digital subtraction angiography (DSA) of cerebral vessels with rotational scanning was performed. Image analysis was performed by the Philips Integris 3D RA device,which is a specialized workstation (Three-Dimensional Rotational Angiography). 3D reconstructions of cerebral arteries were created based on the data. Sixty-six cerebral aneurysms were embolized with hydrogel coils, which expand in contact with blood. reaching the maximum diameter in about 20 minutes. In 29 aneurysms (43.9%), the effect of the procedure was confirmed on a follow-up DSA after 8.0±4.1 months from the initial treatment.

RESULTS

A complete embolization was performed in 55 aneurysms (83.3%), and partial embolization in 11 aneurysms (16.7%). In 6 aneurysms (9.1%), re-embolization was necessary and it resulted in a complete embolization of 5 aneurysms. On a follow-up DSA, complete embolization was present in 25 aneurysms (86.2%), and partial embolization in 4 aneurysms (13.8%), respectively.

CONCLUSIONS

Endovascular embolization with hydrogel coils is an effective and safe treatment method for cerebral aneurysms, although it carries the risk of some complications.

T cell function is dispensable for intracranial aneurysm formation and progression

Given the social importance of intracranial aneurysm as a major cause of a lethal subarachnoid hemorrhage, clarification of mechanisms underlying the pathogenesis of this disease is essential for improving poor prognosis once after rupture. Previous histopathological analyses of human aneurysm walls have revealed the presence of T cells in lesions suggesting involvement of this type of cell in the pathogenesis. However, it remains unclear whether T cell actively participates in intracranial aneurysm progression. To examine whether T cell is involved in aneurysm progression, intracranial aneurysm model of rat was used. In this model, aneurysm is induced by increase in hemodynamic force loaded on bifurcation site of intracranial arteries where aneurysms are developed. Deficiency in T cells and pharmacological inhibition of T cell function were applied to this model. CD3-positive T cells were present in human aneurysm walls, whose number was significantly larger compared with that in control arterial walls. Deficiency in T cells in rats and pharmacological inhibition of T cell function by oral administration of Cyclosporine A both failed to affect intracranial aneurysm progression, degenerative changes of arterial walls and macrophage infiltration in lesions. Although T cells are detectable in intracranial aneurysm walls, their function is dispensable for macrophage-mediated inflammation and degenerative changes in arterial walls, which presumably leads to intracranial aneurysm progression.

Unruptured Cerebral Aneurysms in Elderly Patients

The prevalence of unruptured cerebral aneurysms (UCAs) in elderly patients is increasing in our aging population. UCA management in elderly patients has some difficulties, such as reduced life expectancy, increased comorbidities and treatment risks, and poor prognosis in case of rupture. In this review article, we summarize the most recent findings on the natural history, therapeutic options and treatment results for UCAs exclusively in elderly patients, and describe possible medical treatments for patients with UCAs.

[Tactics of surgical treatment of patients with unruptured asymptomatic cerebral aneurysms]

AIM

To clarify the indications for surgical treatment and the principles for choosing a surgical technique for patients with unruptured asymptomatic aneurysms (UAAs) based on the results of direct and endovasal operations performed at the Burdenko Neurosurgical Institute and on the literature data.

MATERIAL AND METHODS

The study included 694 UAA patients (481 females (69.3%) and 213 males (30.7%)) operated on at the Burdenko Neurosurgical Institute from 1997 to 2013. The patients' age ranged from 1 to 74 years (mean age, 48.3 years). Multiple aneurysms were in 126 (18.2%) patients. Anterior circle of Willis aneurysms were in 92.8% of cases. Among these, internal carotid artery (ICA) aneurysms (46.3%) and middle cerebral artery (MCA) aneurysms (30.8%) were predominant. Microsurgical and endovascular interventions on aneurysms were performed in 665 patients (95.8%).

RESULTS

Complete aneurysm exclusion was achieved in 94.8% of cases. A pronounced neurological deficit developed in 8 (1.2%) patients, and a moderate neurological deficit developed in 62 (9.3%) patients. Postoperative mortality was 0.5%.

CONCLUSION

Surgical treatment of UAAs is associated with low disability and mortality rates. All UAAs need to be operated on, especially in young and middle age patients, if surgery is technically possible, and there are no concomitant diseases contraindicating the intervention. The choice of an UAA exclusion technique is made based on the general principles of surgical treatment of cerebral aneurysms. At present, the method of choice is endovascular surgery for most cases of vertebrobasilar basin and ICA aneurysms and a microsurgical intervention for anterior cerebral artery and MCA aneurysms.

Prevalence and Characteristics of Unruptured Cerebral Aneurysms in Ischemic Stroke Patients

BACKGROUND AND PURPOSE

The prevalence of unruptured cerebral aneurysms (UCAs) in ischemic stroke patients is not clearly defined. This study aimed to measure the prevalence and characteristics of UCAs in patients with acute ischemic stroke (AIS) and to compare our findings with those of the general population. In addition, we investigated the factors associated with cerebral aneurysms in AIS patients.

METHODS

We retrospectively reviewed the brain magnetic resonance angiography images of 955 patients with AIS and 2,118 controls who had received a brain magnetic resonance angiography as part of a health check-up. We investigated the prevalence, size, location, and risk factors of the subjects in the context of UCAs.

RESULTS

UCAs were found in 74 patients with AIS (7.7%) and in 79 who received a health check-up (3.7%). The prevalence of UCAs was significantly higher in the AIS group than in the health check-up group (odds ratio 2.17, 95% confidence interval 1.56-3.01). The mean aneurysm diameter was larger in the AIS group than in the health check-up group (3.75 mm vs. 3.02 mm, P=0.009). UCAs were primarily located in the internal carotid artery in both groups, and aneurysms in the middle cerebral artery were particularly common in the AIS group. According to multivariate analysis, hypertension alone was associated with an increased prevalence of UCAs in stroke patients.

CONCLUSIONS

This study identified a higher prevalence and larger size of UCAs in AIS patients than in the general population. Hypertension was an independent risk factor of UCA in AIS.

Sexual Activity as a Risk Factor for the Spontaneous Rupture of Cerebral Aneurysms

Subarachnoid hemorrhages from ruptured cerebral aneurysms have a high clinical relevance and often lead to death. Approximately 2% to 5% of the people worldwide, even of younger age, are said to have aneurysms at cerebral arteries. In many cases, they remain clinically unapparent for decades. However, there are numerous risk factors for the rupture of an aneurysm, including temporary raises of the blood pressure. Such changes of the blood pressure can be induced even by several everyday behaviors. For example, any sort of sexual activities may cause extensive raises of the blood pressure because of several physical and psychological factors. The term "sexual activity" covers sexual intercourse as well as masturbation. In this article, the remarkable case of a 24-year-old woman with a ruptured cerebral aneurysm in the context of masturbation is presented. It is discussed with respect to the possible pathophysiological effects of sexual activity on cerebral aneurysms.

A Concealed Intracranial Aneurysm Detected after Recanalization of an Occluded Vessel: A Case Report and Literature Review

BACKGROUND

Based on the results of several randomized controlled trials, acute endovascular thrombectomy is strongly recommended for patients with acute ischemic stroke due to large artery occlusion (LAO). The incidence of an intracranial aneurysm has been reported to be approximately 5% in the general population. Therefore, the possibility of the coincidence of LAO and an intracranial aneurysm at the distal part of an occluded vessel should be considered.

SUMMARY

A 74-year-old female patient presented with the sudden onset of consciousness disturbance and left-sided weakness. Neuroimages demonstrated an acute infarction due to right middle cerebral artery occlusion. The occlusion was successfully treated, and an aneurysm was incidentally detected at the occluded artery. We reviewed the literature and identified 11 cases in 8 reports, which were similar to our case. Among the 11 cases, aneurysms ruptured during endovascular therapy in 2 cases. In the present report, we discussed the prediction of concealed aneurysms and avoidance of their rupture during endovascular intervention.

KEY MESSAGE

The presence of an aneurysm concealed behind an embolus should be carefully assessed on preoperative and intraoperative neuroimages. The important findings for suspecting such an aneurysm are a hyperdense nodular sign on preoperative computed tomography and unusual motion of the microwire during the endovascular intervention. Even if there is no finding indicative of an aneurysm, the catheter and thrombectomy devices should be more carefully advanced than usual, especially at the common sites of aneurysms, and the devices should be appropriately chosen.

CTA Characteristics of the Circle of Willis and Intracranial Aneurysm in a Chinese Crowd with Family History of Stroke

BACKGROUND AND PURPOSE

The vascular morphology in crowd with family history of stroke remains unclear. The present study clarified the characteristics of the intracranial vascular CoW and prevalence of intracranial aneurysms in subjects with family history of stroke.

METHODS

A stratified cluster, random sampling method was used for subjects with family history of stroke among rural residents in Jixian, Tianjin, China. All the subjects underwent a physical examination, head computed tomography (CT) scan, and cephalic and cervical computed tomography angiography (CTA) scan. Anatomic variations in the Circle of Willis and cerebrovascular disease in this population were analyzed.

RESULTS

In the crowd with similar living environment, stable genetic background, and family history of stroke and without obvious nerve function impairment (1) hypoplasia or absence of A1 segment was significantly different in gender (male versus female: 9.8% versus 18.8%, p = 0.031), especially the right-side A1 (male versus female: 5.9% versus 16.4%, p = 0.004). (2) Hypoplasia or absence of bilateral posterior communicating arteries was more common in men than women (58.2% versus 45.3%, p = 0.032). Unilateral fetal posterior cerebral artery was observed more often in women than men (17.2% versus 8.5%, p = 0.028). (3) The percentage of subjects with incomplete CoW did not increase significantly with age. Compared to healthy Chinese people, the crowd had a higher percentage of incomplete CoW (p < 0.001). (4) No obvious correlation between risk factors and CoW was found. (5) The prevalence of aneurysm was 10.3% in the special crowd.

CONCLUSIONS

The certain variations of CoW showed significant relation to gender, but not to age in people with family history of stroke. The incomplete circle may be a dangerous factor that is independent of common risk factors for stroke and tend to lead to cerebral ischemia in the crowd with family history of stroke. The prevalence of intracranial aneurysm is comparatively high in the present subjects compared to other people.

Morphological Risk Factors for Rupture of Small (<7 mm) Posterior Communicating Artery Aneurysms

BACKGROUND

The management of small, unruptured intracranial aneurysms is still controversial. Given the distinctive natural history of aneurysm at different locations, location-specific analysis might be a reasonable approach. This study aimed to investigate morphological discriminators for rupture status by focusing on only posterior communicating artery (PcomA) aneurysms smaller than 7 mm.

METHODS

In 108 small PcomA aneurysms (68 ruptured, 40 unruptured), clinical and morphological characteristics were compared between the ruptured and unruptured groups. Multivariate logistic regression analysis was performed to determine the independent predictors for the rupture status of small PcomA aneurysms.

RESULTS

None of the clinical characteristics were significantly different between the ruptured and unruptured groups (P > 0.05). The ruptured group revealed a significantly larger size (P = 0.009), aspect ratio (P = 0.009), size ratio (P = 0.002), dome-to-neck ratio (P = 0.002), inflow angle (P < 0.001), and proportion of bleb formation (P = 0.039). Bottleneck factor (P = 0.154), diameter of PcomA (P = 0.302), and fetal-type PcomA (P = 0.832) showed no significance. With multivariate analyses, size ratio (P = 0.012) and inflow angle (P = 0.001) were shown to be independently associated with the rupture status of small PcomA aneurysms.

CONCLUSIONS

Morphological characteristics were closely related with the rupture status of small PcomA aneurysms. Size ratio and inflow angle were independent risk factors for rupture and might be useful in clinical risk stratification of small PcomA aneurysms.