Size and location of ruptured intracranial aneurysms: consecutive series of 1993 hospital-admitted patients

Deep learning-based platform performs high detection sensitivity of intracranial aneurysms in 3D brain TOF-MRA: An external clinical validation study

PURPOSE

To evaluate the diagnostic efficacy of a developed artificial intelligence (AI) platform incorporating deep learning algorithms for the automated detection of intracranial aneurysms in time-of-flight (TOF) magnetic resonance angiography (MRA).

METHOD

This retrospective study encompassed 3D TOF MRA images acquired between January 2023 and June 2023, aiming to validate the presence of intracranial aneurysms via our developed AI platform. The manual segmentation results by experienced neuroradiologists served as the "gold standard". Following annotation of MRA images by neuroradiologists using InferScholar software, the AI platform conducted automatic segmentation of intracranial aneurysms. Various metrics including accuracy (ACC), balanced ACC, area under the curve (AUC), sensitivity (SE), specificity (SP), F1 score, Brier Score, and Net Benefit were utilized to evaluate the generalization of AI platform. Comparison of intracranial aneurysm identification performance was conducted between the AI platform and six radiologists with experience ranging from 3 to 12 years in interpreting MR images. Additionally, a comparative analysis was carried out between radiologists' detection performance based on independent visual diagnosis and AI-assisted diagnosis. Subgroup analyses were also performed based on the size and location of the aneurysms to explore factors impacting aneurysm detectability.

RESULTS

510 patients were enrolled including 215 patients (42.16 %) with intracranial aneurysms and 295 patients (57.84 %) without aneurysms. Compared with six radiologists, the AI platform showed competitive discrimination power (AUC, 0.96), acceptable calibration (Brier Score loss, 0.08), and clinical utility (Net Benefit, 86.96 %). The AI platform demonstrated superior performance in detecting aneurysms with an overall SE, SP, ACC, balanced ACC, and F1 score of 91.63 %, 92.20 %, 91.96 %, 91.92 %, and 90.57 % respectively, outperforming the detectability of the two resident radiologists. For subgroup analysis based on aneurysm size and location, we observed that the SE of the AI platform for identifying tiny (diameter＜3mm), small (3 mm ≤ diameter＜5mm), medium (5 mm ≤ diameter＜7mm) and large aneurysms (diameter ≥ 7 mm) was 87.80 %, 93.14 %, 95.45 %, and 100 %, respectively. Furthermore, the SE for detecting aneurysms in the anterior circulation was higher than that in the posterior circulation. Utilizing the AI assistance, six radiologists (i.e., two residents, two attendings and two professors) achieved statistically significant improvements in mean SE (residents: 71.40 % vs. 88.37 %; attendings: 82.79 % vs. 93.26 %; professors: 90.07 % vs. 97.44 %; P < 0.05) and ACC (residents: 85.29 % vs. 94.12 %; attendings: 91.76 % vs. 97.06 %; professors: 95.29 % vs. 98.82 %; P < 0.05) while no statistically significant change was observed in SP. Overall, radiologists' mean SE increased by 11.40 %, mean SP increased by 1.86 %, and mean ACC increased by 5.88 %, mean balanced ACC promoted by 6.63 %, mean F1 score grew by 7.89 %, and Net Benefit rose by 12.52 %, with a concurrent decrease in mean Brier score declined by 0.06.

CONCLUSIONS

The deep learning algorithms implemented in the AI platform effectively detected intracranial aneurysms on TOF-MRA and notably enhanced the diagnostic capabilities of radiologists. This indicates that the AI-based auxiliary diagnosis model can provide dependable and precise prediction to improve the diagnostic capacity of radiologists.

Changes in treatment of intracranial aneurysms during the last decade in a large European neurovascular center

OBJECTIVE

Treatment modality for ruptured and unruptured intracranial aneurysms has shifted during the last two decades from microsurgical treatment towards endovascular treatment. We present how this transition happened in a large European neurovascular center.

METHODS

We conducted a retrospective observational study consecutive patients treated for an unruptured or ruptured intracranial aneurysm at Helsinki University Hospital during 2012-2022. We used Poisson regression analysis to report age-adjusted treatment trends by aneurysm location and rupture status.

RESULTS

A total of 2491 patients with intracranial aneurysms were treated (44% ruptured, 56% unruptured): 1421 (57%) surgically and 1070 (43%) endovascularly. A general trend towards fewer treated aneurysms was noted. The proportion of patients treated surgically decreased from 90% in 2012 to 20% in 2022. The age-adjusted decrease of surgical versus endovascular treatment was 6.9%/year for all aneurysms, 6.8% for ruptured aneurysms, and 6.8% for unruptured aneurysms. The decrease of surgical treatment was most evident in unruptured vertebrobasilar aneurysms (10.8%/year), unruptured communicating artery aneurysms (10.1%/year), ruptured communicating artery aneurysms (10.0%/year), and ruptured internal carotid aneurysms (9.0%/year). There was no change in treatment modality for middle cerebral artery aneurysms, of which 85% were still surgically treated in 2022. A trend towards an increasing size for treated ruptured aneurysms was found (p = 0.033).

CONCLUSION

A significant shift of the treatment modality from surgical to endovascular treatment occurred for all aneurysm locations except for middle cerebral artery aneurysms. Whether this shift has affected long-term safety and patient outcomes should be assessed in the future.

Microsurgical treatment of posterior circulation aneurysms: an institutional experience from Nepal

Background

Management strategies and outcomes of patients with posterior circulation aneurysms are varied due to uncertainty in the optimal treatment modality and limited experience of neurosurgeons. Data are scarce regarding patients with posterior circulation aneurysms from developing countries. This study aims to describe the clinical characteristics, management strategies and outcome of patients with these aneurysms treated microsurgically in an academic institute in Nepal.

Methods

The clinical records of patients confirmed to have posterior circulation aneurysms treated microsurgically between July 2014 and July 2022 were retrospectively reviewed. Demographic and clinical characteristics, morphometric characteristics of aneurysms, management strategies, postoperative complications, and 1-year outcomes were described.

Results

Out of 220 aneurysms in 190 patients, 20 were posterior circulation aneurysms. The median age of the patients was 43 (15-60) years. All were ruptured aneurysms. The admission Hunt and Hess grades of 18 (90%) patients were less than or equal to III. The posterior inferior cerebellar artery (8) was the commonest location. The postoperative complications rate was 20%, with the overall mortality of 10%. 80% of patients had a favourable outcome at 1-year follow-up.

Conclusions

The patient characteristics and outcome are comparable with those described in the literature from other countries. With an individualized and careful selection strategy, our results are satisfactory despite fewer operations.

Trend of cerebral aneurysms over the past two centuries: need for early screening

OBJECTIVE

Cerebral aneurysms (CAs) are linked to variations in the cerebral basal arterial network (CBAN). This study aimed to find the optimal age for screening to detect brain arterial variations and predict aneurysms before rupture.

DESIGN

An observational, quantitative and retrospective research.

SETTING

The study analysed 1127 cases of CAs published from 1761 to 1938. Additionally, CT angiography images of 173-patients at the Royal Adelaide Hospital (RAH), South Australia between 2011 and 2019 were examined for the presence and the location of aneurysms in CBAN.

PARTICIPANTS

The data were collected from patients at RAH and 407 published sources, including males and females across the entire age range, up to 100 years old.

OUTCOME MEASURES AND RESULTS

Data, CAs cases, from 1761 to 1938 included (526 males, 573 females and 28 unknown sexes). The age of these patients varied from 18 months to 89 years (mean age=42, SD=18). Approximately 11.5% of the CAs occurred in patients aged <20 years. Among the 1078 aneurysms whose location was reported, 76% were located in the internal carotid (IC), middle cerebral (MC) and anterior communicating artery complex (AcomAC) regions, while the remaining 24% were in the vertebrobasilar region. Among 173 patients from RAH aged between 18 and 100 years (male=83 and female=90, mean age=60, SD=16), 94% of the CAs were found in the IC, MC and AcomAC regions. The pattern of aneurysm occurrence, as indicated by values at the 25th, 50th and 75th percentiles, along with the minimum and maximum patient ages, has remained consistent from 1761 to 2019.

CONCLUSION

The distribution pattern of CAs in relation to sex, age and locations in the CBAN, remained steady over the last 260 years resulting in risk of strokes early in life. Therefore, early screening for CBAN segment variations is advised for stroke prevention if possible.

Intracranial aneurysm wall displacement depicted by amplified Flow predicts growth

BACKGROUND

Abnormal intracranial aneurysm (IA) wall motion has been associated with IA growth and rupture. Recently, a new image processing algorithm called amplified Flow (aFlow) has been used to successfully track IA wall motion by combining the amplification of cine and four-dimensional (4D) Flow MRI. We sought to apply aFlow to assess wall motion as a potential marker of IA growth in a paired-wise analysis of patients with growing versus stable aneurysms.

METHODS

In this retrospective case-control study, 10 patients with growing IAs and a matched cohort of 10 patients with stable IAs who had baseline 4D Flow MRI were included. The aFlow was used to amplify and extract IA wall displacements from 4D Flow MRI. The associations of aFlow parameters with commonly used risk factors and morphometric features were assessed using paired-wise univariate and multivariate analyses.

RESULTS

aFlow quantitative results showed significantly (P=0.035) higher wall motion displacement depicted by mean±SD 90th% values of 2.34±0.72 in growing IAs versus 1.39±0.58 in stable IAs with an area under the curve of 0.85. There was also significantly (P<0.05) higher variability of wall deformation across IA geometry in growing versus stable IAs depicted by the dispersion variables including 121-150% larger standard deviation ([Formula: see text]) and 128-161% wider interquartile range [Formula: see text].

CONCLUSIONS

aFlow-derived quantitative assessment of IA wall motion showed greater wall motion and higher variability of wall deformation in growing versus stable IAs.

Constrained estimation of intracranial aneurysm surface deformation using 4D-CTA

BACKGROUND AND OBJECTIVE

Intracranial aneurysms are relatively common life-threatening diseases, and assessing aneurysm rupture risk and identifying the associated risk factors is essential. Parameters such as the Oscillatory Shear Index, Pressure Loss Coefficient, and Wall Shear Stress are reliable indicators of intracranial aneurysm development and rupture risk, but aneurysm surface irregular pulsation has also received attention in aneurysm rupture risk assessment.

METHODS

The present paper proposed a new approach to estimate aneurysm surface deformation. This method transforms the estimation of aneurysm surface deformation into a constrained optimization problem, which minimizes the error between the displacement estimated by the model and the sparse data point displacements from the four-dimensional CT angiography (4D-CTA) imaging data.

RESULTS

The effect of the number of sparse data points on the results has been discussed in both simulation and experimental results, and it shows that the proposed method can accurately estimate the surface deformation of intracranial aneurysms when using sufficient sparse data points.

CONCLUSIONS

Due to a potential association between aneurysm rupture and surface irregular pulsation, the estimation of aneurysm surface deformation is needed. This paper proposed a method based on 4D-CTA imaging data, offering a novel solution for the estimation of intracranial aneurysm surface deformation.

Case Fatality of Aneurysmal Subarachnoid Hemorrhage Varies by Geographic Region Within Finland: A Nationwide Register-Based Study

BACKGROUND AND OBJECTIVES

Previous studies have reported a substantial between-country variation in the case fatality rates (CFRs) of aneurysmal subarachnoid hemorrhage (SAH). However, contrary to comparisons among countries, nationwide comparisons within countries that focus on populations with equal access to health care and include out-of-hospital deaths in analyses are lacking. Thus, we aimed to investigate whether the SAH CFRs vary between geographic regions within Finland.

METHODS

We identified all hospitalized and nonhospitalized (sudden-death) cases with aneurysmal SAH in Finland during 1998-2017 through 2 externally validated nationwide registers. According to the municipality of residence, we divided the cases with SAH into 5 geographic regions: Southern, Central, Western, Northern, and Eastern Finland, each served by a University Central Hospital with a neurosurgical service. In addition to overall 30-day CFRs, we computed sudden death rates and 30-day CFRs after hospitalization for each region. Using logistic and Poisson regression models, we calculated regional age-adjusted, sex-adjusted, and year-adjusted odds ratios and annual percent changes with 95% CIs for CFRs.

RESULTS

During 1998-2017, we identified a total of 9,443 cases with SAH, of which 3,484 (36.9%) occurred in Southern Finland. In comparison with the overall 30-day CFR of Southern Finland (35.1%), the age-adjusted, sex-adjusted, and study year-adjusted odds of SAH death were 32% (16%-50%) higher in Central Finland (42.7%), 39% (23%-58%) higher in Eastern Finland (43.4%), and 52% (33%-74%) higher in Western Finland (47.1%). The regional differences were present among both sexes, in all age groups, in sudden death rates, and in 30-day CFRs after hospitalization. Between 1998 and 2017, the overall 30-day CFRs decreased in Central (2.4% [1.0%-3.8%] per year) and Southern (1.2% [0.2%-2.2%] per year) Finland, whereas CFRs remained stable in the other regions. In the last 4 years of the study period (2014-2017), Southern Finland had the lowest 30-day CFR (16.5%) among hospitalized patients.

DISCUSSION

SAH CFRs seem to vary significantly even within a country with relatively equal access to health care. Future studies with detailed individual-level data are needed to explore whether health inequities explain the reported findings.

Correlation between the rate of morphological changes and rupture of intracranial aneurysms during one cardiac cycle analyzed by 4D-CTA

Objective

This study aimed to analyze the relationship between the rate of morphological changes and intracranial aneurysm rupture during the cardiac cycle.

Methods

Eighty-four patients with intracranial aneurysms were retrospectively analyzed and divided into the rupture (42 cases) and unruptured (42 cases) groups. Four-dimensional computed tomography angiography (4D-CTA) was performed to collect quantitative parameters of aneurysm morphology and calculate the morphological change rate. The potential factors associated with aneurysm rupture were determined by comparing the general clinical data and rate of change in the location and morphology of the aneurysm between the two groups.

Results

Each morphological change rate in the rupture group was generally higher than that of the unruptured group. The rate of dome height change and aneurysm volume change were independent factors associated with aneurysm rupture. ROC curve analysis revealed that the diagnostic accuracy of the aneurysm volume change rate was higher. When the volume change rate was 12.33%, the sensitivity and specificity of rupture were 90.5 and 55.8%, respectively.

Conclusion

The rate of change in dome height and volume of intracranial aneurysms during one cardiac cycle were independent factors associated with aneurysm rupture.

Predictors of intraoperative intracranial aneurysm rupture in patients with subarachnoid hemorrhage: a retrospective analysis

PURPOSE

Intraoperative cerebral aneurysm rupture (IOR) is a common phenomenon with a frequency of around 19%. Research regarding IOR lacks an analysis of its predictors.

METHODS

We retrospectively examined all saccular aneurysms, in 198 patients with subarachnoid hemorrhage, surgically treated from 2013 to 2019. Operative reports, patient histories, blood test results, discharge summaries, and radiological data were reviewed. IOR was defined as any bleeding from the aneurysm during surgery, preceding putting a clip on its neck, regardless of how trivial.

RESULTS

The frequency of IOR was 20.20%. Patients with IOR had higher aneurysm dome size (9.43 ± 8.39 mm vs. 4.96 ± 2.57 mm; p < 0.01). The presence of blood clot on the aneurysm dome was significantly associated with IOR (12.50% vs. 2.53%; p < 0.01). We also associated lamina terminalis fenestration during surgery (7.50% vs. 21.52%; p = 0.04) and multiple aneurysms (5.00% vs. 18.35%; p = 0.038) with a lower risk of IOR. Glucose blood levels were also elevated in patients with IOR (7.47 ± 2.78 mmol/l vs. 6.90 ± 2.22 mmol/l; p = 0.04). Multivariate analysis associated that urea blood levels (OR 0.55, 0.33 to 0.81, p < 0.01) and multiple aneurysms (OR 0.04, 0.00 to 0.37, p = 0.014) were protective factors against the occurrence of IOR.

CONCLUSION

Large dome size of an aneurysm, a blood clot on the aneurysm dome and elevated glucose blood levels can be IOR predictive. Lamina terminalis fenestration, the appearance of multiple aneurysms, and high urea blood levels may be associated with a lower risk of such an event.

Hemodynamics of thrombus formation in intracranial aneurysms: An in silico observational study

How prevalent is spontaneous thrombosis in a population containing all sizes of intracranial aneurysms? How can we calibrate computational models of thrombosis based on published data? How does spontaneous thrombosis differ in normo- and hypertensive subjects? We address the first question through a thorough analysis of published datasets that provide spontaneous thrombosis rates across different aneurysm characteristics. This analysis provides data for a subgroup of the general population of aneurysms, namely, those of large and giant size (>10 mm). Based on these observed spontaneous thrombosis rates, our computational modeling platform enables the first in silico observational study of spontaneous thrombosis prevalence across a broader set of aneurysm phenotypes. We generate 109 virtual patients and use a novel approach to calibrate two trigger thresholds: residence time and shear rate, thus addressing the second question. We then address the third question by utilizing this calibrated model to provide new insight into the effects of hypertension on spontaneous thrombosis. We demonstrate how a mechanistic thrombosis model calibrated on an intracranial aneurysm cohort can help estimate spontaneous thrombosis prevalence in a broader aneurysm population. This study is enabled through a fully automatic multi-scale modeling pipeline. We use the clinical spontaneous thrombosis data as an indirect population-level validation of a complex computational modeling framework. Furthermore, our framework allows exploration of the influence of hypertension in spontaneous thrombosis. This lays the foundation for in silico clinical trials of cerebrovascular devices in high-risk populations, e.g., assessing the performance of flow diverters in aneurysms for hypertensive patients.

Clinical and Morphological Factors for Ruptured Anterior Communicating Artery Aneurysms

Introduction

The anterior communicating artery (ACoA) aneurysm, the most frequent cerebral aneurysm to rupture, carries a significant clinical burden, yet the factors influencing its rupture are limited in Indonesia. This study aims to determine the clinical and morphological features associated with ruptured ACoA compared to non-AcoA aneurysms among Indonesians.

Patients and Methods

We retrospectively reviewed our center's aneurysm patient registry from January 2019 to December 2022, and compared the clinical and morphological features between ruptured ACoA aneurysms and ruptured aneurysms elsewhere with univariate and multivariate analyses.

Results

Of the 292 patients with 325 ruptured aneurysms, 89 were from ACoA. The mean age of patients was 54.99 years, with female preponderance in the non-ACoA group (non-ACoA: 73.31%, ACoA: 46.07%). On univariate analysis, ages ≥60 [ages 60-69: OR = 0.311 (0.111-0.869), p=0.026; ages ≥70: OR = 0.215 (0.056-0.819), p=0.024], female gender [OR = 0.311 (0.182-0.533), p<0.001], and smoking [OR=2.069 (1.036-4.057), p=0.022] exhibited significant association with ruptured ACoA aneurysm. On multivariate analysis, only the female gender was independently associated with ruptured ACoA aneurysm (aOR 0.355 [0.436-1.961], p=0.001).

Conclusion

In our study, ruptured ACoA aneurysm was inversely associated with advanced age, female gender, presence of daughter aneurysm, and directly associated with smoking. After multivariate adjustment, the female gender showed an independent association with ruptured ACoA aneurysm.

A comparison of endovascular coil systems for the treatment of small intracranial aneurysms

BACKGROUND

Endovascular coiling of small, intracranial aneurysms remains controversial and difficult, despite advances in technology.

METHODS

We retrospectively reviewed data for 62 small aneurysms (<3.99 mm) in 59 patients. Occlusion rates, complications rates, and coil packing densities were compared between subgroups based upon coil type and rupture status.

RESULTS

Ruptured aneurysms predominated (67.7%). Aneurysms measured 2.99 ± 0.63 mm by 2.51 ± 0.61 mm with an aspect ratio of 1.21 ± 0.34 mm. Brands included Optima (Balt) (29%), MicroVention Hydrogel (24.2%), and Penumbra SMART (19.4%) coil systems. Average packing density was 34.3 ± 13.5 mm³. Occlusion rate was 100% in unruptured aneurysms; 84% utilized adjuvant devices. For ruptured aneurysms, complete occlusion or stable neck remnant was achieved in 88.6% while recanalization occurred in 11.4%. No rebleeding occurred. Average packing density (p = 0.919) and coil type (p = 0.056) did not impact occlusion. Aspect ratio was smaller in aneurysms with technical complications (p = 0.281), and aneurysm volume was significantly smaller in those with coil protrusion (p = 0.018). Complication rates did not differ between ruptured and unruptured aneurysms (22.6 vs. 15.8%, p = 0.308) or coil types (p = 0.830).

CONCLUSION

Despite advances in embolization devices, coiling of small intracranial aneurysms is still scrutinized. High occlusion rates are achievable, especially in unruptured aneurysms, with coil type and packing density suggesting association with complete occlusion. Technical complications may be influenced by aneurysm geometry. Advances in endovascular technologies have revolutionized small aneurysm treatment, with this series demonstrating excellent aneurysm occlusion especially in unruptured aneurysms.

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.

Utility of flow diverters in treatment of acutely ruptured uncoilable aneurysms of the posterior circulation of the brain

PURPOSE

Aim of this study is to evaluate safety and efficacy of flow diverters (FDs) in treatment of acutely ruptured posterior circulation aneurysms MATERIALS AND METHODS: Databases of three participating institutions were retrospectively scanned for patients in whom FD placement was attempted for treatment of acutely ruptured vertebrobasilar aneurysms. An interval of 14 days or fewer between the latest ictus and treatment was used as inclusion criterion. Patients with dolichoectasia of vertebrobasilar arteries were excluded. If necessary, adjunctive techniques including coiling or stenting were utilized. Clinical outcomes were graded using mWFNS (modified World Federation of Neurosurgical Societies Scale) and mRS (modified Rankin Scale). Aneurysmal occlusion was defined as Raymond-Roy Class 1. Spearman's (ρ) test was used to assess the correlation between variables. Univariate and multivariate logistic regression were used to assess outcomes.

RESULTS

31 patients (25 women, mean age: 52.7 ± 15.2) harboring 32 aneurysms (16 non-saccular, mean size: 11.4 ± 7 mm) were included. Mean number of FDs used was 1.22 ± 0.42. In six cases, adjunctive coiling and in five cases, apposing stent placement were used. Overall mortality rate and procedure-related mortality rates were 22.5% (7/31) and 9.6% (3/31), respectively. At a mean imaging follow-up of 17.2 ± 12.6 months, total occlusion was achieved in 22 aneurysms (91.6%). Univariate analysis showed that mortality was positively correlated with vasospasm (ρ = 0.600, p < 0.05), higher mWFNS Scale (ρ = 0.685, p < 0.05), higher modified Fischer Score (ρ = 0.609, p < 0.05), higher mRS (ρ = 0.594, p < 0.05) on admission and negatively correlated with saccular morphology (ρ = -0.529, p < 0.05). Multivariate logistic regression identified mWFNS on admission as a significant predictor. (OR: 7.148, 95% CI 1.777-28.758, p: 0.01). Adjunctive coiling positively correlated with aneurysm occlusion. (ρ = 0.522, p < 0.05).

CONCLUSION

The procedure-related morbidity and mortality is not negligible. However, the risks and efficacy associated with FDs are acceptable, especially when adjunctive coiling is possible, given the lack of treatment alternatives.

Novel Superior Cerebellar Artery Aneurysm Coming from a Superior Cerebellar Artery-Posterior Cerebral Artery Anastomotic Branch

A middle-aged patient presented with subarachnoid hemorrhage and was found to have a ruptured superior cerebellar artery (SCA) aneurysm arising from the origin of a rare anastomotic branch between the right SCA and right posterior cerebral artery (PCA). The aneurysm was secured by transradial coil embolization, and the patient made a good functional recovery. This case demonstrates an aneurysm arising from an anastomotic branch between the SCA and PCA, which may represent a remnant of a persistent primordial hindbrain channel. Although variations in basilar artery branches are common, aneurysms rarely can form at the site of seldom- seen anastomoses between the branches of the posterior circulation. The complex embryology of these vessels, which includes anastomoses and the involution of primitive arteries, may have contributed to the development of this aneurysm arising from an SCA-PCA anastomotic branch.

Small intracranial aneurysms of the anterior circulation: A negligible risk?

BACKGROUND AND PURPOSE

According to the International Study of Unruptured Intracranial Aneurysms, small (<7 mm) unruptured intracranial aneurysms (IAs) of the anterior circulation (aC) carry a neglectable 5-year rupture risk. In contrast, some studies report frequencies of >20% of all ruptured IAs being small IAs of the aC. This contradiction was addressed in this study by analyzing the rates and risk factors for rupture of small IAs within the aC.

METHODS

Of the institutional observational cohort, 1676 small IAs of the aC were included. Different demographic, clinical, laboratory, and radiographic characteristics were collected. A rupture risk score was established using all independent prognostic factors. The score performance was checked using receiver operating characteristic curve analysis.

RESULTS

Of all registered small IAs of the aC, 20.1% were ruptured. The developed small IAs of the aC (SIAAC) score (range = -4 to +13 points) contained five major risk factors: IA location and size, arterial hypertension, alcohol abuse, and chronic renal failure. In addition, three putative protective factors were also included in the score: hypothyroidism, dyslipidemia, and peripheral arterial disease. Increasing rates of ruptured IA with increasing SIAAC scores were observed, from 0% (≤-1 points) through >50% (≥8 points) and up to 100% in patients scoring ≥12 points. The SIAAC score achieved excellent discrimination (area under the curve_SIAAC  = 0.803) and performed better than the PHASES (Population,Hypertension, Age, Size of the aneurysm, Earlier SAH from another aneurysm, Site of aneurysm) score.

CONCLUSIONS

Small IAs of the aC carry a considerable rupture risk. After external validation, the proposed rupture risk score might provide a basis for better decision-making regarding the treatment of small unruptured IAs of the aC.

Case Fatality in Patients With Aneurysmal Subarachnoid Hemorrhage in Finland: A Nationwide Register-Based Study

BACKGROUND AND OBJECTIVES

Although single-center studies have reported declining case fatality rates (CFRs) of aneurysmal subarachnoid hemorrhage (SAH), nationwide reports that also include sudden-death SAHs with long uninterrupted study periods have remained limited. Moreover, little is known about whether the time-dependent trends of SAH CFR differ by age and/or sex. Thus, we aimed to characterize the nationwide changes of SAH CFRs in Finland between 1998 and 2017.

METHODS

We used 2 externally validated nationwide registers to identify all hospitalized and nonhospitalized (sudden-death) aneurysmal SAH events in Finland during 1998-2017. In addition to overall 30-day CFRs, we determined annual proportions of sudden-death and 30-day CFRs among hospitalized patients with SAH. To estimate time-dependent trends, we calculated annual age-adjusted and sex-adjusted CFR changes (percent with 95% CIs).

RESULTS

Between 1998 and 2017, we identified 9,443 cases with SAH (57.6% women), of which 2,245 (23.8%) died before hospitalization and 3,715 (39.3%) died within 30 days after SAH. Among the 7,198 hospitalized patients with SAH, the 30-day CFR was 20.4%. During the study period, the overall age-adjusted and sex-adjusted CFR declined by an average of 1.8% (1.1%-2.6%) per year. The decreases were especially notable in the proportion of sudden deaths among middle-aged (aged 40-64 years) and older (aged 65 years or older) women (2.9% [1.1%-4.7%] and 2.3% [0.7%-4.0%] per year, respectively) and in the CFRs of hospitalized young (younger than 40 years) and middle-aged women (9.1% [2.3%-15.7%] and 4.3% [2.3%-6.5%] per year, respectively). On the contrary, the 30-day CFR of older (aged 65 years or older) hospitalized men increased by 3.5% (0.7%-6.3%) per year, while the proportions of older men who died before hospitalization remained unchanged.

DISCUSSION

The overall CFR of SAH seems to be decreasing, at least among women. The continued high CFR of hospitalized older men requires attention from clinicians and epidemiologists, especially if this trend is also common in other countries.

Deep learning-based recognition and segmentation of intracranial aneurysms under small sample size

The manual identification and segmentation of intracranial aneurysms (IAs) involved in the 3D reconstruction procedure are labor-intensive and prone to human errors. To meet the demands for routine clinical management and large cohort studies of IAs, fast and accurate patient-specific IA reconstruction becomes a research Frontier. In this study, a deep-learning-based framework for IA identification and segmentation was developed, and the impacts of image pre-processing and convolutional neural network (CNN) architectures on the framework's performance were investigated. Three-dimensional (3D) segmentation-dedicated architectures, including 3D UNet, VNet, and 3D Res-UNet were evaluated. The dataset used in this study included 101 sets of anonymized cranial computed tomography angiography (CTA) images with 140 IA cases. After the labeling and image pre-processing, a training set and test set containing 112 and 28 IA lesions were used to train and evaluate the convolutional neural network mentioned above. The performances of three convolutional neural networks were compared in terms of training performance, segmentation performance, and segmentation efficiency using multiple quantitative metrics. All the convolutional neural networks showed a non-zero voxel-wise recall (V-Recall) at the case level. Among them, 3D UNet exhibited a better overall segmentation performance under the relatively small sample size. The automatic segmentation results based on 3D UNet reached an average V-Recall of 0.797 ± 0.140 (3.5% and 17.3% higher than that of VNet and 3D Res-UNet), as well as an average dice similarity coefficient (DSC) of 0.818 ± 0.100, which was 4.1%, and 11.7% higher than VNet and 3D Res-UNet. Moreover, the average Hausdorff distance (HD) of the 3D UNet was 3.323 ± 3.212 voxels, which was 8.3% and 17.3% lower than that of VNet and 3D Res-UNet. The three-dimensional deviation analysis results also showed that the segmentations of 3D UNet had the smallest deviation with a max distance of +1.4760/-2.3854 mm, an average distance of 0.3480 mm, a standard deviation (STD) of 0.5978 mm, a root mean square (RMS) of 0.7269 mm. In addition, the average segmentation time (AST) of the 3D UNet was 0.053s, equal to that of 3D Res-UNet and 8.62% shorter than VNet. The results from this study suggested that the proposed deep learning framework integrated with 3D UNet can provide fast and accurate IA identification and segmentation.

The incidence and prevalence of unruptured intracranial aneurysms in sickle cell disease patients: a systematic review

BACKGROUND

Unruptured Intracranial Aneurysms (UIAs) pose a significant risk of morbidity in the general population and much more so among sickle cell disease (SCD) patients. Meanwhile, the proportion of these patients with UIAs is not established just as the course and characteristics of the aneurysms are not well known.

AIM

To estimate the prevalence, incidence and characteristics of UIAs in SCD patients and compare same with the metrics and features in the general population.

METHODS

The Data repositories, Medline (PubMed), Embase and Web of science were systematically searched from January 1st, 1990, to July 31st, 2021. Publications that passed an inclusion test were reviewed for data on the incidence and prevalence of UIAs, aneurysm characteristics and outcomes in SCD patients extracted. Findings from the included studies were appraised, using the Methodological Index for Non-randomized studies score (MINORS). The results were descriptively analysed. Given the marked heterogeneity of retrieved data, results were reported as standardized values, including the mean weighted annual incidence rate.

RESULTS

105 SCD patients with 186 UIAs were identified in 10 retrospective studies. Mean age ranged from 10.5 to 40.18 across studies with adult (>18 years) predominance. The prevalence of UIAs in SCD was 4.1% (95%CI 3.6 and 4.6) incidence rate was 1290.3/100,000 patient-years (95% CI 1018.0-1562.6). Aneurysms tended to be small (60%), anterior (76.1%), multiple (45.7%), and managed conservatively (62%) with mostly good outcomes (95%). The average MINORS score was 9.4 ± 3.1 for non-comparative studies (n = 8) and 19.5 ± 0.7 for comparative studies (n = 2).

CONCLUSION

UIAs have a definite relationship with SCD, with higher incidence figures relative to the general population. Aneurysmal characteristics although largely similar, tend to be smaller in SCD patients. The low methodological quality of reviewed studies informs the need for well-designed prospective randomized controlled studies to better understand the mechanics of this relationship.

Dexmedetomidine alleviates inflammatory response and oxidative stress injury of vascular smooth muscle cell via α2AR/GSK-3β/MKP-1/NRF2 axis in intracranial aneurysm

Vascular smooth muscle cell (VSMC) phenotypic modulation regulates the initiation and progression of intracranial aneurysm (IA). Dexmedetomidine (DEX) is suggested to play neuroprotective roles in patients with craniocerebral injury. Therefore, we investigated the biological functions of DEX and its mechanisms against IA formation and progression in the current study. The rat primary VSMCs were isolated from Sprague-Dawley rats. IA and superficial temporal artery (STA) tissue samples were obtained from patients with IA. Flow cytometry was conducted to identify the characteristics of isolated VSMCs. Hydrogen peroxide (H₂O₂) was used to mimic IA-like conditions in vitro. Cell viability was detected using CCK-8 assays. Wound healing and Transwell assays were performed to detect cell motility. ROS production was determined by immunofluorescence using DCFH-DA probes. Western blotting and RT-qPCR were carried out to measure gene expression levels. Inflammation responses were determined by measuring inflammatory cytokines. Immunohistochemistry staining was conducted to measure α₂-adrenergic receptor levels in tissue samples. DEX alleviated the H₂O₂-induced cytotoxicity, attenuated the promoting effects of H₂O₂ on cell malignancy, and protected VSMCs against H₂O₂-induced oxidative damage and inflammation response. DEX regulated the GSK-3β/MKP-1/NRF2 pathway via the α2AR. DEX alleviates the inflammatory responses and oxidative damage of VSMCs by regulating the GSK-3β/MKP-1/NRF2 pathway via the α2AR in IA.

Risk factors for aneurysm rupture among Kazakhs: findings from a national tertiary

BACKGROUND

Rupture of intracranial aneurysms (RIA) leads to subarachnoid hemorrhage (SAH) with severe consequences. Although risks for RIA are established, the results vary between ethnic groups and were never studied in Kazakhstan. This study aimed to establish the risk factors of RIA in the Kazakh population.  METHODS: Retrospective analysis of 762 patients with single IAs, who attended the neurosurgical center from 2008 until 2018, was conducted. Demographic characteristics, such as age, sex, smoking status, and hypertension were considered. Descriptive and bivariate analyses were performed. A multivariable logistic regression model was built to identify factors correlated with RIA.

RESULTS

The mean age of participants was 48.49 ± 0.44 years old. The majority (68.37%) of IAs have ruptured. Of the ruptured aneurysms, 43.76% were < 6 mm, and 38.39% were located on the anterior cerebral and anterior communicating arteries (ACA). Logistic regression model indicates younger age group (16-40 years), smoking, having stage 3 hypertension, smaller IA size and its location on ACA increase the odds of rupture.

CONCLUSIONS

This study has revealed that younger, smoking patients with stage 3 arterial hypertension are at higher risk for RIA. Small aneurysms (< 6 mm) and location on ACA had increased odds of rupture, while larger aneurysms on internal carotid arteries had lower odds.

A web-based dynamic nomogram for rupture risk of posterior communicating artery aneurysms utilizing clinical, morphological, and hemodynamic characteristics

Background

Predicting rupture risk is important for aneurysm management. This research aimed to develop and validate a nomogram model to forecast the rupture risk of posterior communicating artery (PcomA) aneurysms.

Methods

Clinical, morphological, and hemodynamic parameters of 107 unruptured PcomA aneurysms and 225 ruptured PcomA aneurysms were retrospectively analyzed. The least absolute shrinkage and selection operator (LASSO) analysis was applied to identify the optimal rupture risk factors, and a web-based dynamic nomogram was developed accordingly. The nomogram model was internally validated and externally validated independently. The receiver operating characteristic (ROC) curve was used to assess the discrimination of nomogram, and simultaneously the Hosmer–Lemeshow test and calibration plots were used to assess the calibration. Decision curve analysis (DCA) and clinical impact curve (CIC) were used to evaluate the clinical utility of nomogram additionally.

Results

Four optimal rupture predictors of PcomA aneurysms were selected by LASSO and identified by multivariate logistic analysis, including hypertension, aspect ratio (AR), oscillatory shear index (OSI), and wall shear stress (WSS). A web-based dynamic nomogram was then developed. The area under the curve (AUC) in the training and external validation cohorts was 0.872 and 0.867, respectively. The Hosmer–Lemeshow p > 0.05 and calibration curves showed an appropriate fit. The results of DCA and CIC indicated that the net benefit rate of the nomogram model is higher than other models.

Conclusion

Hypertension, high AR, high OSI, and low WSS were the most relevant risk factors for rupture of PcomA aneurysms. A web-based dynamic nomogram thus established demonstrated adequate discrimination and calibration after internal and external validation. We hope that this tool will provide guidance for the management of PcomA aneurysms.

Nomogram model for predicting oculomotor nerve palsy in patients with intracranial aneurysm

AIM

To explore the risk factors of oculomotor nerve palsy (ONP) in patients with intracranial aneurysm (IA) and develop a nomogram model for predicting ONP of IA patients.

METHODS

A total of 329 IA patients were included. Logistic regression analysis was applied to identify independent factors, which were then integrated into the nomogram model. The performance of the nomogram model was evaluated by calibration curve, receiver operating curve (ROC), and decision curve analysis.

RESULTS

Univariate and multivariate logistic regression analysis indicated posterior communicating artery (PCoA) aneurysm [hazard ratio (HR)=17.13, P<0.001] and aneurysm diameter (HR=1.31, P<0.001) were independent risk factors of ONP in IA patients. Based on the results of logistic regression analysis, a nomogram model for predicting the ONP in IA patients was constructed. The calibration curve indicated the nomogram had a good agreement between the predictions and observations. The nomogram showed a high predictive accuracy and discriminative ability with an area under the curve (AUC) of 0.863. The decision curve analysis showed that the nomogram was powerful in the clinical decision. PCoA aneurysm (HR=3.38, P=0.015) was identified to be the only independent risk factor for ONP severity.

CONCLUSION

PCoA aneurysm and aneurysm diameter are independent risk factors of ONP in IA patients. The nomogram established is performed reliably and accurately for predicting ONP. PCoA aneurysm is the only independent risk factor for ONP severity.

Unruptured cerebral aneurysm risk stratification: Background, current research, and future directions in aneurysm assessment

Background:

The optimal management of unruptured cerebral aneurysms is widely debated in the medical field. Rapid technology advances, evolving understanding of underlying pathophysiology, and shifting practice patterns have made the cerebrovascular field particularly dynamic in recent years. Despite progress, there remains a dearth of large randomized studies to help guide the management of these controversial patients.

Methods:

We review the existing literature on the natural history of unruptured cerebral aneurysms and highlight ongoing research aimed at improving our ability to stratify risk in these patients.

Results:

Landmark natural history studies demonstrated the significance of size, location, and other risk factors for aneurysm rupture, but prior studies have significant limitations. We have begun to understand the underlying pathophysiology behind aneurysm formation and rupture and are now applying new tools such as flow dynamics simulations and machine learning to individualize rupture risk stratification.

Conclusion:

Prior studies have identified several key risk factors for aneurysmal rupture, but have limitations. New technology and research methods have enabled us to better understanding individual rupture risk for patients with unruptured cerebral aneurysms.

What Are the Predictors of Intracranial Aneurysm Rupture in Indonesian Population Based on Angiographic Findings? Insight from Intracranial Aneurysm Registry on Three Comprehensive Stroke Centres in Indonesia

Objectives

What are the Predictors of Intracranial Aneurysm (IA) Rupture based on angiographic findings among patients in Indonesia's Population Based on Angiographic Findings.

Materials and Methods

We conducted a cross-sectional study on subjects with IA not caused by congenital aetiologies or other vascular malformations with cerebral angiography performed from January 2017 to January 2021. Demographic data and aneurysm profile, which include aneurysm count, size, location, and rupture event, were collected. The correlation between risk factors and IA rupture events was determined using bivariate and multivariate analysis.

Results

From 100 angiography data (33 males and 67 females), the mean subject age is 51.94 ± 10.78. We observe a total of 121 IAs from all subjects. Most of the IAs are in the anterior circulation (104 aneurysms, 85.96%), have small size (77 aneurysms, 63.64%), and are found in ruptured conditions (90 aneurysms, 74.38%). Males have a greater aneurysm count (1.36 ± 0.74 vs. 1.13 ± 0.55, p = 0.036) and larger aneurysm size (p = 0.002). Aneurysm size is significantly correlated with its location (p = 0.008). Medium size (p = 0.019; OR 2.62, 95% CI 1.08-6.36) and location other than the internal carotid artery are associated with increased rupture event. Multivariate analysis revealed that gender (p = 0.031; aOR 5.37, 95% CI 1.17-24.70) is a significant risk factor of IA rupture event.

Conclusion

IA profiling will enable clinicians to determine the risk of rupture and treatment plans for the Indonesian population. Further studies with a larger sample size are required to confirm these findings.

Risk Factors for Pericallosal Artery Aneurysm Rupture Based on Morphological Computer-Assisted Semiautomated Measurement and Hemodynamic Analysis

Background: Although pericallosal artery aneurysms (PAAs) are relatively uncommon, accounting for only 1-9% of all intracranial aneurysms (IAs), they exhibit a considerably high propensity to rupture. Nevertheless, our current knowledge of the risk factors for PAA rupture is still very limited. To fill this gap, we investigated rupture risk factors for PAAs based on morphological computer-assisted semiautomated measurement (CASAM) and hemodynamic analysis. Methods: Patients with PAAs were selected from the IA database in our institute and their baseline data were collected. Morphological parameters were measured in all enrolled patients by applying CASAM. Computational fluid dynamics simulation (CFD) was performed to evaluate the hemodynamic difference between ruptured and unruptured PAAs. Results: From June 2017 to June 2020, among 2141 patients with IAs in our institute, 47 had PAAs (2.2%). Thirty-one patients (mean age 57.65 ± 9.97 years) with 32 PAAs (20 unruptured and 12 ruptured) were included in the final analysis. Comparing with unruptured PAAs, ruptured PAAs had significantly higher aspect ratio (AR), mean normalized wall shear stress (NWSS), and mean oscillatory shear index (OSI) values than the unruptured PAAs (all P < 0.05) in univariate analyses. Multivariable analysis showed that a high mean OSI was an independent risk factor for PAA rupture (OR = 6.45, 95% CI 1.37-30.32, P = 0.018). Conclusion: This preliminary study indicates that there are morphological and hemodynamic differences between ruptured and unruptured PAAs. In particular, a high mean OSI is an independent risk factor for PAA rupture. Further research with a larger sample size is warranted in the future.

Imaging versus Intervention in Managing Small Unruptured Intracranial Aneurysms: A Cost-Effectiveness Analysis

OBJECTIVE

Current guidelines recommend active surveillance with serial magnetic resonance angiography (MRA) for management of small, asymptomatic unruptured anterior circulation aneurysms (UIAs). We sought to determine the cost-effectiveness of active surveillance compared to immediate surgery.

METHODS

We developed a Markov cost-effectiveness model simulating patients with small (<7 mm) UIAs managed by active surveillance via MRA, immediate surgery, or watchful waiting. Inputs for the model were abstracted from the literature and used to construct a comprehensive model following persons from diagnosis to death. Outcomes were quality-adjusted life-years (QALYs), lifetime medical costs (2015 USD), and incremental cost-effectiveness ratios (ICERs). Cost-effectiveness, deterministic, and probabilistic sensitivity analyses were performed.

RESULTS

Immediate surgical treatment was the most cost-effective management strategy for small UIAs with ICER of USD 45,772 relative to active surveillance. Sensitivity analysis demonstrated immediate surgery was the preferred strategy, if rupture rate was >0.1%/year and if the diagnosis age was <70 years, while active surveillance was preferred if surgical complication risk was >11%. Probabilistic sensitivity analysis demonstrated that at a willingness-to-pay of USD 100,000/QALY, immediate surgical treatment was the most cost-effective strategy in 64% of iterations.

CONCLUSION

Immediate surgical treatment is a cost-effective strategy for initial management of small UIAs in patients <70 years of age. While more costly than MRA, surgical treatment increased QALY. The cost-effectiveness of immediate surgery is highly sensitive to diagnosis age, rupture rate, and surgical complication risk. Though there are a wide range of rupture rates and complications associated with treatment, this analysis supports the treatment of small, unruptured anterior circulation intracranial aneurysms in patients <70 years of age.

Assessing the utility and accuracy of ICD10-CM non-traumatic subarachnoid hemorrhage codes for intracranial aneurysm research

BACKGROUND

The 10th revision of International Classification of Disease, Clinical Modification (ICD10-CM) increased the number of codes to identify non-traumatic subarachnoid hemorrhage from 1 to 22. ICD10-CM codes are able to specify the location of aneurysms causing subarachnoid hemorrhage (aSAH); however, it is not clear how frequently or accurately these codes are being used in practice.

OBJECTIVE

To systematically evaluate the usage and accuracy of location-specific ICD10-CM codes for aSAH.

METHODS

We extracted all uses of ICD10-CM codes for non-traumatic subarachnoid hemorrhage (I60.x) during the first 3 years following the implementation of ICD10-CM from the billing module of the electronic health record (EHR) for UCHealth. For those codes that specified aSAH location (I60.0-I60.6), EHR documentation was reviewed to determine whether there was an active aSAH, any patient history of aSAH, or unruptured intracranial aneurysm/s and the locations of those outcomes.

RESULTS

Between 1 October 2015 and 30 September 2018, there were 3119 instances of non-traumatic subarachnoid hemorrhage ICD10-CM codes (I60.00-I60.9), of which 297 (9.5%) code instances identified aSAH location (I60.0-I60.6). The usage of location-specific codes increased from 5.7% in 2015 to 11.2% in 2018. These codes accurately identified current aSAH (64%), any patient history of aSAH (84%), and any patient history of intracranial aneurysm (87%). The accuracy of identified outcome location was 53% in current aSAH, 72% for any history of aSAH, and 76% for any history of an intracranial aneurysm.

CONCLUSIONS

Researchers should use ICD10-CM codes with caution when attempting to detect active aSAH and/or aneurysm location.

Relationship between cerebral aneurysms and variations in cerebral basal arterial network: a morphometric cross-sectional study in Computed Tomography Angiograms from a neurointerventional unit

OBJECTIVE

Segments of cerebral basal arterial network (CBAN) dampen the peak pressure in blood flowing through these arteries, thus minimising the chances of development of cerebral aneurysms. The objective of this research was to find the relationship of occurrence of intracranial aneurysms to variations of the components of the CBAN.

DESIGN AND SETTING

This is an observational, quantitative and retrospective research, which used cerebral CT angiography (CCTA) images.

PARTICIPANTS

Cerebral CTA of 145 adult patients of both sexes were studied.

MAIN OUTCOME MEASURES

Diameters of segments of CBAN were measured in CCTA images and the relative size of each vessel was calculated to standardise for differences in overall arterial sizes among patients. Relationships among sizes of CBAN components were analysed. Presence of aneurysms in different parts of the CBAN was recorded.

RESULTS

Forty-six aneurysms in right internal carotid artery (ICA) and middle cerebral artery (MCA) and 32 aneurysms in left ICA and MCA segments were noted in 42 and 30 patients, respectively. Aneurysms in anterior communicating artery complex and vertebral-basilar arterial segments were seen in 27 and 8 patients, respectively, while they were not detected in parts of posterior cerebral artery (PCA). The significant (p<0.001) inverse relationships between sizes of posterior communicating artery and the first segment of PCA on both sides indicated that blood inputs to the second part of PCA were similar. Difference in means of the index of arterial size variation for people with aneurysms (mean 0.96, SD 0.23) and without aneurysms (mean 0.86, SD 0.22) was significant (p=0.015).

CONCLUSION

Variation in segments of CBAN was quantified. The peak pressure dampening mechanism in such arterial segments reduces the chances of development of aneurysms.

AngioSuite-Assisted Volume Calculation and Coil Use Prediction in the Endovascular Treatment of Tiny Volume Intracranial Aneurysms

Methods

Thirty-three consecutive patients with 34 TVIAs were prospectively recruited and treated with endovascular techniques. The volume of TVIAs and the required length of coils were calculated by the AngioSuite software before embolization. The treatment efficacy of TVIAs was assessed using the Raymond scale (Rs) and the modified Rankin scale (mRs).

Results

Of the 34 aneurysms with an average volume of 7.16 mm³, 13 aneurysms were treated with sole coil embolization, 19 by stent-assisted embolization, and 2 by balloon-assisted embolization. The average coil length was 5.32 cm, and the average packing density was 41.21%. The immediate DSA showed that total occlusion (Rs = 1) was achieved in 15 aneurysms, subtotal (Rs = 2) in 9, and partial (Rs = 3) in 11. Total occlusion was achieved in 30 aneurysms and subtotal in the other 4 aneurysms at 6-month follow-up. Baseline volume and diameter of aneurysms were significantly correlated with the coil length (r = 0.801, P < 0.001; r = 0.711, P < 0.001).

Conclusions

Coil embolization of TVIAs was easy to achieve high packing density. According to the data from AngioSuite, relative few coils can increase the safety in procedure and stenting may reduce risk of aneurysmal recurrence.

Substantial Within-Country Variation in the Incidence of Subarachnoid Hemorrhage: A Nationwide Finnish Study

OBJECTIVE

To study whether the incidence of subarachnoid hemorrhage (SAH) varies between geographic regions of Finland.

METHODS

By utilizing the nationwide Causes of Death and Hospital Discharge Registers, we identified all first-ever, hospitalized, and sudden-death (dying before hospitalization) SAH events in Finland between 1998 and 2017. Based on the patients' home residence, we divided SAHs into 5 geographic regions: southern, central, western, eastern, and northern Finland. We calculated crude and European age-standardized (European Standard Population [ESP] 2013) SAH incidence rates for each region and used a Poisson regression model to calculate age-, sex-, and calendar year-adjusted incidence rate ratios (IRRs) and 95% confidence intervals for regional and time-dependent differences.

RESULTS

During the total 106,510,337 cumulative person-years, we identified 9,443 first-ever SAH cases, of which 24% resulted in death before hospitalization. As compared to western Finland, where the SAH incidence was the lowest (7.4 per 100,000 persons), the ESP-standardized SAH incidence was 1.4 times higher in eastern (10.2 per 100,000 persons; adjusted IRR, 1.37 [1.27-1.47]) and northern Finland (10.4 per 100,000 persons; adjusted IRR, 1.40 [1.30-1.51]). These differences were similar when men and women were analyzed independently. Although SAH incidence rates decreased in all 5 regions over 2 decades, the rate of decrease varied significantly by region.

CONCLUSION

SAH incidence appears to vary substantially by region in Finland. Our results suggest that regional SAH studies can identify high-risk subpopulations, but can also considerably over- or underestimate incidence on a nationwide level.

Endovascular Treatment of Ruptured Wide-Necked Anterior Communicating Artery Aneurysms Using a Low-Profile Visualized Intraluminal Support (LVIS) Device

Objective: To evaluate the safety and efficacy of low-profile visualized intraluminal support (LVIS) stent-assisted coiling for the treatment of ruptured wide-necked anterior communicating artery (ACoA) aneurysms.

Methods: The clinical and angiographic data of 31 acutely ruptured wide-necked ACoA aneurysms treated with LVIS stent-assisted coiling between January 2014 and December 2018 were retrospectively reviewed.

Results: All stents were successfully deployed. The immediate angiographic results were modified Raymond-Roy class I in 27 cases, modified Raymond-Roy class II in 2 cases, and modified Raymond-Roy class IIIa in 2 cases. Intraoperative thrombosis and postoperative aneurysmal rebleeding occurred in one case each. Two patients (6.5%) who were admitted due to poor clinical grade conditions died during hospital admission as a result of initial bleeding. Angiographic follow-up (mean: 12.9 months) was performed for 26 patients, the results of which demonstrated that 25 aneurysms were completely occluded and one was class II. The last clinical follow-up (mean: 25.3 months) outcomes demonstrated that 27 patients had favorable clinical outcomes and two had poor clinical outcomes.

Conclusion: LVIS stent-assisted coiling for ruptured wide-necked ACoA aneurysms was safe and effective, with a relatively low rate of perioperative complications and a high rate of complete occlusion at follow-up.

Current Knowledge of and Perspectives about the Pathogenesis of Blood Blister-like Aneurysms of the Internal Carotid Artery: A Review of the Literature

Blood blister-like aneurysms (BBAs) are rare and usually appear at nonbranching sites in the supraclinoid portion of the internal carotid artery (ICA). Because it is difficult to obtain histological specimens of the aneurysm wall and because experimental models are challenging to establish, the pathogenesis of BBAs remains uncertain. In this paper, we reviewed the diagnostic, radiological, and pathophysiological characteristics of patients with BBAs. We also summarized the existing evidence and potential mechanisms related to the causes of BBAs. Current evidence indicates that atherosclerosis and dissection are the main prerequisites for the formation of BBAs. Hemodynamics may play a role in the process of BBA formation due to the unique vascular anatomy of the supraclinoid ICA. Further research on histopathology and hemodynamics is warranted in this field.

Survey of European neurosurgeons' management of unruptured intracranial aneurysms: inconsistent practice and organization

Background

The discovery of an unruptured intracranial aneurysm creates a dilemma between observation and treatment. Neurosurgeons’ routines for risk assessment and treatment decision-making are unknown. The position of evidence-based medicine in European neurosurgery is considered to be weak, high-grade guidelines do not exist and variations between institutions are probable. We aimed to explore European neurosurgeons’ management routines for newly discovered unruptured intracranial aneurysms.

Methods

In cooperation with the European Association of Neurosurgical Societies (EANS), we conducted an online, cross-sectional survey of 420 European neurosurgeons during Spring/Summer 2016 (1533 non-Norwegians invited through the EANS, and 16 Norwegians invited through heads of departments because of the need for additional information for a separate study). We asked about demographic variables, routines for management and risk assessment of newly discovered unruptured intracranial aneurysms and presented a case. We collected information about gross domestic product (GDP) per capita from the International Monetary Fund.

Results

The response rate to the invite from the EANS was 26%, with respondents from 47 countries. More than half of the respondents (n = 226 [54%]) reported that their department treated less than 25 unruptured aneurysms yearly. Forty percent said their department used aneurysm size cut-off to guide treatment decisions, with a mean size of 6 mm. Presented with a case, respondents from countries with a lower GDP per capita recommended intervention more often than respondents from higher-income countries. Vascular neurosurgeons more commonly recommended observation.

Conclusion

The answers to this self-reported survey indicate that many centers have a treatment volume lower than recommended by international guidelines, and that there are socioeconomic differences in care. Better documentation of treatment and outcome, for example with clinical quality registries, is needed to drive improvements of care.

Electronic supplementary material

The online version of this article (10.1007/s00701-020-04539-8) contains supplementary material, which is available to authorized users.

Amplified Flow Imaging (aFlow): A Novel MRI-Based Tool to Unravel the Coupled Dynamics Between the Human Brain and Cerebrovasculature

With each heartbeat, periodic variations in arterial blood pressure are transmitted along the vasculature, resulting in localized deformations of the arterial wall and its surrounding tissue. Quantification of such motions may help understand various cerebrovascular conditions, yet it has proven technically challenging thus far. We introduce a new image processing algorithm called amplified Flow (aFlow) which allows to study the coupled brain-blood flow motion by combining the amplification of cine and 4D flow MRI. By incorporating a modal analysis technique known as dynamic mode decomposition into the algorithm, aFlow is able to capture the characteristics of transient events present in the brain and arterial wall deformation. Validating aFlow, we tested it on phantom simulations mimicking arterial walls motion and observed that aFlow displays almost twice higher SNR than its predecessor amplified MRI (aMRI). We then applied aFlow to 4D flow and cine MRI datasets of 5 healthy subjects, finding high correlations between blood flow velocity and tissue deformation in selected brain regions, with correlation values r = 0.61 , 0.59, 0.52 for the pons, frontal and occipital lobe ( ). Finally, we explored the potential diagnostic applicability of aFlow by studying intracranial aneurysm dynamics, which seems to be indicative of rupture risk. In two patients, aFlow successfully visualized the imperceptible aneurysm wall motion, additionally quantifying the increase in the high frequency wall displacement after a one-year follow-up period (20%, 76%). These preliminary data suggest that aFlow may provide a novel imaging biomarker for the assessment of aneurysms evolution, with important potential diagnostic implications.

Clinical features of and risk factors for intracranial aneurysms associated with moyamoya disease

BACKGROUND

The clinical features of aneurysms associated with moyamoya disease (MMD) and risk factors for the formation and rupture of aneurysms are not well defined.

AIMS

In this study, we retrospectively analyzed clinical data of MMD patients and examined the potential risk factors for the formation and rupture of aneurysms in these patients.

METHODS

The medical records of all MMD patients in our hospital from April 2012 to May 2019 were reviewed. The logistic regression analysis was used to determine the independent association between various potential risk factors and the presence or rupture of intracranial aneurysms in MMD patients.

RESULTS

Of 2230 MMD patients, 182 (8.2%) cases had intracranial aneurysms. The mean age of onset in patients with aneurysms was 47.2 years, which was significantly higher when compared with those without aneurysms (p < 0.001). In logistic regression analysis, age of onset remained significantly associated with the presence of intracranial aneurysms, while female gender, hypertension, diabetes mellitus, and coronary artery disease were not. Besides, intracranial aneurysms were significantly associated with intracranial hemorrhage in MMD patients (odds ratio [OR] = 5.19; 95% confidence interval [CI], 3.80-7.09). About 60% aneurysms >5 mm in size, and 62.1% aneurysms with irregularly shaped morphology were ruptured. Aneurysms located in basilar tip, collateral or moyamoya vessels were more likely to present with rupture.

CONCLUSIONS

Age was an important risk factor for intracranial aneurysms formation in MMD patients. Aneurysms increased the risk of intracerebral hemorrhage in MMD patients, and their ruptures were correlated with aneurysms size, location, and morphology.

Aging Changes of Aneurysmal Subarachnoid Hemorrhage: A 35-year, Hospital-Based Study

BACKGROUND

The etiology and background factors which cause decreases in the size of ruptured intracranial aneurysms remain unclear.

OBJECTIVE

To clarify the age- and sex-related differences in aneurysmal subarachnoid hemorrhage (SAH) based on a 35-year-old hospital database and demographic data.

METHODS

A database of patients admitted to our hospital with aneurysmal SAH from 1983 to 2017 was split into 5-year intervals and analyzed. Demographic data of the general population were also analyzed for reference.

RESULTS

Altogether, 1,523 aneurysmal SAH events were enrolled in the analysis. Age (p<0.001), proportion of elderly patients ≥ 65 years old (p<0.001), female sex (p=0.005), very small aneurysms less than 5 mm (p<0.001), and the yearly-averaged number of fatal events showed increasing trends. The proportion of aneurysm size of 10 mm or more (p = 0.011) and the yearly-averaged population of Shimane prefecture (p < 0.001) showed declining trends. In the subgroup analyses, the proportion of very small aneurysms was found to increase significantly in the non-elderly male and elderly female subgroups. The proportion of large aneurysms (10 mm or more) decreased in the non-elderly subgroup (p<0.05). As for the elderly subgroups, the yearly-averaged number of events did not show a significant tendency, although the yearly-averaged population of Shimane prefecture showed an increasing trend.

CONCLUSION

We found an increasing trend in the prevalence of very small aneurysms in elderly females. Recent aging may contribute to this trend. The number of aneurysmal SAH events was confirmed to not increase, despite the increased aging population of Shimane prefecture.

Impact of Ruptured Aneurysm Circulation on Mortality: A Nationwide Inpatient Sample Analysis

OBJECTIVE

This study investigates the effect of aneurysm circulation on mortality and patient outcomes after aneurysmal subarachnoid hemorrhage (SAH) within the United States.

METHODS

A retrospective cohort study was conducted using the Nationwide Inpatient Sample (NIS), a part of the Healthcare Cost and Utilization Project (HCUP), with ICD-10 codes for non-traumatic SAH between 2015-2016. Aneurysms were stratified as either anterior or posterior circulation. Multivariate logistic regression was used to find the impact of selected variables on the odds of mortality.

RESULTS

The NIS reported 1,892 cases of non-traumatic SAH within the study period that were predominantly anterior circulation (82.6%), female (68.6%), white (57.7%), with mean age of 59.07 years, and in-hospital mortality of 21.4%. Anterior circulation aneurysms were associated with lower severity of initial illness (p = 0.014) but higher likelihood of vasospasm (p = 0.0006) than those of the posterior circulation. In a multivariate logistic regression analysis, mortality was associated with posterior circulation aneurysms (OR: 1.42; CI 95% 1.005-20.10, p = 0.047), increasing age (OR: 1.035; 95% CI 1.022-1.049; p < 0.0001), and shorter hospital stays (OR: 0.7838; 95% CI 0.758-0.811; p < 0.0001). Smoking history (OR: 0.825; 95% CI 0.573-1.187, p > 0.05) and vasospasm (OR: 1.005; 95% CI 0.648-1.558; p > 0.05) were not significantly associated with higher odds of mortality.

CONCLUSIONS

Mortality following aneurysmal SAH is associated with posterior circulation aneurysms, and increasing age, but not smoking history or vasospasm. These findings may be useful for prognostication and counseling patients and families.

Risk factors involved in the formation of multiple intracranial aneurysms

BACKGROUND

Although several risk factors of the multiple intracranial aneurysms (MIAs) formation has been reported, the results are controversial. We aimed to find out the risk factors of MIAs formation by analyzing our clinic data combined with a meta-analysis.

MATERIAL AND METHODS

A retrospective review work of medical records for the patients with aneurysms was undertaken. Univariate analysis was used to examine all mentioned variables. Binary logistic regression analysis was used to identify the risk factors of MIAs formation.

RESULTS

In the retrospective review work, a total of 565 patients with aneurysm were included in this study. Of these 565 participants, 449 patients suffered SIAs and 116 patients suffered MIAs. Univariate analysis showed a significant difference in terms of female, cigarette smoking, family history of hypertension, and primary hypertension between the SIAs and MIAs group. The binary logistic regression analysis showed that the female (OR = 1.624), primary hypertension (OR = 1.563), and family history of hypertension (OR = 2.496) were independent risk factors of the formation of MIAs (for each P < 0.05). With regard to the meta-analysis results, it revealed that there was significant difference in the rates of female (P < 0.001), cigarette smoking (P < 0.001), primary hypertension (P = 0.001), and higher age (P = 0.011) among the MIAs patients.

CONCLUSIONS

A higher rate of the formation of MIAs is closely associated with the elder and female. Patients with hypertension history, cigarette smoking, and family primary hypertension history also affected the formation of MIAs, these risk factors should be a guard against.

Four-Dimensional Magnetic Resonance Imaging Assessment of Intracranial Aneurysms: A State-of-the-Art Review

Treatment of unruptured intracranial aneurysms can reduce the risk of subarachnoid hemorrhage and its associated morbidity and mortality. However, current methods to predict the risk of rupture and optimize treatment strategies for intracranial aneurysms are limited. Assessment of intra-aneurysmal flow using 4-dimensional magnetic resonance imaging (4D MRI) is a novel tool that could be used to guide therapy. A systematic search of the literature was performed to provide a state-of-the-art review on 4D MRI assessment of unruptured intracranial aneurysms. A total of 18 studies were available for review. Eccentric flow on 4D MRI is associated with a greater aspect ratio and peak wall shear stress (WSS). WSS, vorticity, and peak velocity are greater in saccular than fusiform aneurysms. Unstable aneurysms are associated with greater WSS, peak wall stress, and flow jet angle and may exhibit wall enhancement. In comparison to computational fluid dynamics (CFD), 4D MRI has a lower spatial resolution and reports lower WSS and velocity magnitudes, but these parameters equalize when spatial resolution is matched. 4D MRI demonstrates the intra-aneurysmal hemodynamic changes associated with flow diversion, including significantly decreased flow velocity. Thus, 4D MRI is a novel, noninvasive imaging tool used for the evaluation of hemodynamics within intracranial aneurysms. Hemodynamic indices derived from 4D MRI appear to correlate well with the simulated (CFD) values and may be used to measure the success of endovascular therapies and risk factors for aneurysm growth and rupture.

Small Intracranial Aneurysms and Subarachnoid Hemorrhage: Is the Size Criterion for Risk of Rupture Relevant?

The current understanding is that small intracranial aneurysms (<7 mm) are not at a significant risk for rupture. However, there have been several published series of rupture and subarachnoid hemorrhage from aneurysms <5 mm. Three cases of intracranial aneurysms rupturing at <3 mm are presented in this paper. Patient age ranged between 38 and 57 years. The aneurysms were located in different parts of the circulation in the brain. This case series highlights that the size criterion alone is not adequate when evaluating patients with unruptured brain aneurysms for observational follow-up or treatment.

Surgical clipping of ophthalmic artery aneurysms: a single center series

AIM

The purpose of this study was to summary the characteristics of ophthalmic artery (OphA) aneurysms and to obtain the independent risk factors for poor prognosis of microsurgical clipping treatment for OphA aneurysms.

METHODS

The clinical and microsurgical clipping results of all 63 patients with ophthalmic aneurysm were investigated and reviewed. The OphA aneurysm patient's case records were reviewed including clinical characteristics, image findings, and clinical outcomes. Then, the risk factors of poor prognosis were analyzed retrospectively.

RESULTS

Monocular blindness persisted in 4 patients (6.35%), 1 patient developed persistent vegetate state (PVS) (1.59%), while 4 patients (6.35%) died. The matching process constructed a cohort consisting of 9 poor outcome (Glasgow Outcome Scale, GOS 1-3) patients (14.3%), and 54 good outcome (GOS 4-5) patients (85.7%). Univariate analysis between the good outcome and poor outcome revealed statistical significance in age > 60 (p = 0.045), size (p = 0.016), and rupture before operation (p = 0.049). Further, multivariate logistic regression analysis identified age > 60 (odds ratio [OR], 5.877; 95% confidence interval [CI], 1.039-33.254; p = 0.045) and aneurysm size > 10mm (OR, 9.417; 95% CI, 1.476-60.072; p = 0.018) as the independent risk factors for poor outcome in microsurgical clipping treatment for OphA aneurysms.

CONCLUSION

The significant independent risk factors associated with clipping OphA aneurysms are age (>60) and size (>10mm).

Is Anatomical Variations a Risk Factor for Cerebral Vasospasm in Anterior Communicating Complex Aneurysms Rupture?

Background and Purpose- One-third of ruptured aneurysms are located on the anterior communicating complex with high prevalence of anatomic variations of this arterial segment. In this study, we hypothesized that anatomic variations of the anterior communicating complex increase the risk of angiographic vasospasm. Methods- Retrospective study of prospectively collected data from a monocentric subarachnoid hemorrhage cohort of patients admitted to neurointensive care between 2002 and 2018. Univariate followed by multivariate logistic regression analysis was used to identify factors associated with angiographic vasospasm. Results- One thousand three hundred seventy-four patients with aneurismal subarachnoid hemorrhage were admitted to our institution; 29.8% (n=410) were related to an anterior communicating complex aneurysm rupture; 9.2% (n=38) of them showed an anterior communicating artery variation. Angiographic vasospasm was diagnosed in 55.6% of this subgroup (vs 28.1%, P=0.003). In the multivariate analysis, external ventricular drain (2.2 [1.32-3.65], P=0.003) and anterior communicating artery variation (2.40 [1.2-4.9], P=0.04) were independently and significantly associated with angiographic vasospasm, while age above 60 years (0.3 [0.2-0.7]; P=0.002) was a protective factor. However, anterior communicating artery variation was not statistically associated with ischemic vasospasm or poor neurological outcome after anterior communicating artery aneurysm rupture. Conclusions- Anatomic variation of anterior communicating artery could be a new biomarker to identify patients at risk to develop angiographic vasospasm post-subarachnoid hemorrhage. External validation cohorts are necessary to confirm these results.

Prerupture Intracranial Aneurysm Morphology in Predicting Risk of Rupture: A Matched Case-Control Study

BACKGROUND

Maximal size and other morphological parameters of intracranial aneurysms (IAs) are used when deciding if an IA should be treated prophylactically. These parameters are derived from postrupture morphology. As time and rupture may alter the aneurysm geometry, possible morphological predictors of a rupture should be established in prerupture aneurysms.

OBJECTIVE

To identify morphological parameters of unruptured IAs associated with later rupture.

METHODS

Nationwide matched case-control study. Twelve IAs that later ruptured were matched 1:2 with 24 control IAs that remained unruptured during a median follow-up time of 4.5 (interquartile range, 3.7-8.2) yr. Morphological parameters were automatically measured on 3-dimensional models constructed from angiograms obtained at time of diagnosis. Cases and controls were matched by aneurysm location and size, patient age and sex, and the PHASES (population, hypertension, age, size of aneurysm, earlier subarachnoid hemorrhage from another aneurysm, and site of aneurysm) score did not differ between the 2 groups.

RESULTS

Only inflow angle was significantly different in cases vs controls in univariate analysis (P = .045), and remained significant in multivariable analysis. Maximal size correlated with size ratio in both cases and controls (P = .015 and <.001, respectively). However, maximal size and inflow angle were correlated in cases but not in controls (P = .004. and .87, respectively).

CONCLUSION

A straighter inflow angle may predispose an aneurysm to changes that further increase risk of rupture. Traditional parameters of aneurysm morphology may be of limited value in predicting IA rupture.

One-stage Operation with Ipsilateral Two-Piece Craniotomies for a Case of Subarachnoid Hemorrhage with Multiple Intracranial Aneurysms

Subarachnoid hemorrhage (SAH) with multiple intracranial aneurysms is common, but the difficulties often arise in determining treatment strategy in the acute phase. We experienced a case of SAH with distal anterior cerebral artery aneurysm coexisting with middle cerebral artery and anterior communicating artery aneurysms, in which it was difficult to identify the precise rupture site preoperatively, and both pterional approach and interhemispheric approach were required in the acute phase of SAH. However, we could treat whole aneurysms in one stage and obtained an excellent outcome using our surgical procedure with ipsilateral frontotemporal and frontal parasagittal craniotomies through a single skin incision.

Potential Therapeutic Strategies for Intracranial Aneurysms Targeting Aneurysm Pathogenesis

Subarachnoid hemorrhage resulting from intracranial aneurysms (IAs) is associated with high rates of morbidity and mortality. Although trigger mechanisms in the pathogenesis of IAs have not been fully elucidated, accumulating evidence has demonstrated that inflammation acts as a critical contributor to aneurysm pathogenesis. IAs is initiated by disruption and dysfunction of endothelial cells (ECs) caused by abnormal wall shear stress (WSS). Subsequently, vascular inflammation can trigger a series of biochemical reactions resulting in vascular smooth muscle cell (VSMC) apoptosis and migration, accompanied by inflammatory cell infiltration, secretion of various cytokines, and inflammatory factors. These changes result in degradation of vascular wall, leading to the progression and eventual rupture of IAs. Increasing our knowledge of the pathogenesis of these lesions will offer physicians new options for prevention and treatment. In this study, we review aneurysmal pathogenesis to seek for safe, effective, and non-invasive therapeutic strategies.

Ruptured posterior circulation aneurysms: epidemiology, patterns of care, and outcomes from the Swiss SOS national registry

BACKGROUND

The treatment of ruptured posterior circulation aneurysms remains challenging despite progresses in the endovascular and neurosurgical techniques.

OBJECTIVE

To provide epidemiological characterization of subjects presenting with ruptured posterior circulation aneurysms in Switzerland and thereby assessing the treatment patterns and neurological outcomes.

METHODS

This is a retrospective analysis of the Swiss SOS registry for patients with aneurysmal subarachnoid hemorrhage. Patients were divided in 3 groups (upper, lower, and middle third) according to aneurysm location. Clinical, radiological, and treatment-related variables were identified and their impact on the neurological outcome was determined.

RESULTS

From 2009 to 2014, we included 264 patients with ruptured posterior circulation aneurysms. Endovascular occlusion was the most common treatment in all 3 groups (72% in the upper third, 68% in the middle third, and 58.8% in the lower third). Surgical treatment was performed in 11.3%. Favorable outcome (mRS ≤ 3) was found in 56% at discharge and 65.7% at 1 year. No significant difference in the neurological outcome were found among the three groups, in terms of mRS at discharge (p = 0.20) and at 1 year (p = 0.18). High WFNS grade, high Fisher grade at presentation, and rebleeding before aneurysm occlusion (p = 0.001) were all correlated with the risk of unfavorable neurological outcome (or death) at discharge and at 1 year.

CONCLUSIONS

In this study, endovascular occlusion was the principal treatment, with a favorable outcome for two-thirds of patients at discharge and at long term. These results are similar to high volume neurovascular centers worldwide, reflecting the importance of centralized care at specialized neurovascular centers.

Is it dangerous to treat spontaneous intracerebral hemorrhage by minimally invasive surgery plus local thrombolysis in patients with coexisting unruptured intracranial aneurysms?

OBJECTIVES

Limited evidence supports the presumed increased frequency of hemorrhage caused by the unruptured intracranial aneurysms which coexist in patients with spontaneous intracerebral hemorrhage treated with minimally invasive surgery plus local thrombolysis. Subsequently, we sought to determine the safety of local thrombolysis for this particular subset of patients.

PATIENTS AND METHODS

We reviewed the medical records of patients treated with minimally invasive surgery plus local thrombolysis for intracerebral hemorrhage between November 2013 to December 2015 in an intensive care unit of a tertiary care hospital. Depending upon the vascular images, unruptured intracranial aneurysms were identified. The primary outcome was any of postoperative intracranial rebleeding. The second outcome included the 30-day death and 6-month follow up graded by Modified Rank Scale. Blind abstractors reviewed the medical data and binary logistic regression was performed to investigate the risk factors of poor prognosis.

RESULTS

We identified a cohort of consecutive 188 patients, of whom 23 (12.2%) harbored unruptured intracranial aneurysms. There were 28 aneurysms documented in this study, among which 3 were in the posterior circulation. And in total, 20 (11.3%) cases suffered from postoperative hematoma growth, of which 4 were with aneurysms. Additionally,the 30-day mortality after stroke in patients with aneurysms was 8.69% (2/23), comparable to 13.33% in without (22/165,p = 0.744). The proportion of the favorable outcome at 6-month follow-up in patients with aneurysms was comparable to that in without (47.8% versus 48.5%,p = 1.000) Insignificant associations were demonstrated between the unruptured intracranial aneurysms and postoperative intracranial rehemorrhage (p = 0.092), 30-day death(p = 0.588) and poor long-term prognosis (p = 0.332), respectively.

CONCLUSION

Our findings suggest that unruptured intracranial aneurysms seem to represent no increased risks of poor outcome after local thrombolysis for intracerbral hematomas.

Serum Cadmium Level Is Positively Associated with Unruptured Intracranial Aneurysm Incidence

Background

Cadmium is a toxic element in cigarette smoke associated with ischemic vascular disease. Its association with cerebral aneurysm is unknown.

Methods

We retrospectively analyzed the medical records of patients with headache who underwent imaging studies between March 2014 and August 2016. An unruptured intracranial aneurysm (UIA) was confirmed by brain magnetic resonance angiography or computed tomography angiography. A control group included age- and sex-matched patients without an UIA. Whole blood and random urine tests were used for detection of cadmium and arsenic levels, respectively. Student t-test was used to compare subject characteristics, mean cadmium and arsenic levels between groups, and differences between groups with small (<4-mm) and large (≥4-mm) UIAs. Multivariate regression analysis was used to identify risk factors for aneurysm incidence.

Results

Of 238 patients, 25 had an UIA. Those with an UIA had more pack-years of smoking (19.5±3.8 vs. 12.5±6.8, P=0.044) and higher mean serum cadmium levels (1.77±0.19 vs. 0.87±0.21 µg/L, P=0.027). Arsenic levels showed no difference between groups. (67.4±23.5 vs. 62.2±18.3 µg/L, P=0.458). There were no significantly different demographic, clinical, or laboratory characteristics between small and large aneurysm groups. According to multivariate analysis, smoking (odds ratio [OR], 1.48; 95% confidence interval [CI], 1.06–2.33; P=0.047) and serum cadmium >2.0 mcg/L (OR, 1.39; 95% CI, 1.15–1.84; P=0.043) were associated with aneurysm incidence.

Conclusion

UIA incidence was associated with pack-years of smoking and serum cadmium level, but aneurysm size was not associated with serum cadmium level.