Unruptured intracranial aneurysms not undergoing preventive endovascular or neurosurgical treatment are often monitored radiologically to detect aneurysm growth, which is associated with an increase ...in risk of rupture. However, the absolute risk of aneurysm rupture after detection of growth remains unclear.
To determine the absolute risk of rupture of an aneurysm after detection of growth during follow-up and to develop a prediction model for rupture.
Individual patient data were obtained from 15 international cohorts. Patients 18 years and older who had follow-up imaging for at least 1 untreated unruptured intracranial aneurysm with growth detected at follow-up imaging and with 1 day or longer of follow-up after growth were included. Fusiform or arteriovenous malformation-related aneurysms were excluded. Of the 5166 eligible patients who had follow-up imaging for intracranial aneurysms, 4827 were excluded because no aneurysm growth was detected, and 27 were excluded because they had less than 1 day follow-up after detection of growth.
All included aneurysms had growth, defined as 1 mm or greater increase in 1 direction at follow-up imaging.
The primary outcome was aneurysm rupture. The absolute risk of rupture was measured with the Kaplan-Meier estimate at 3 time points (6 months, 1 year, and 2 years) after initial growth. Cox proportional hazards regression was used to identify predictors of rupture after growth detection.
A total of 312 patients were included (223 71% were women; mean SD age, 61 12 years) with 329 aneurysms with growth. During 864 aneurysm-years of follow-up, 25 (7.6%) of these aneurysms ruptured. The absolute risk of rupture after growth was 2.9% (95% CI, 0.9-4.9) at 6 months, 4.3% (95% CI, 1.9-6.7) at 1 year, and 6.0% (95% CI, 2.9-9.1) at 2 years. In multivariable analyses, predictors of rupture were size (7 mm or larger hazard ratio, 3.1; 95% CI, 1.4-7.2), shape (irregular hazard ratio, 2.9; 95% CI, 1.3-6.5), and site (middle cerebral artery hazard ratio, 3.6; 95% CI, 0.8-16.3; anterior cerebral artery, posterior communicating artery, or posterior circulation hazard ratio, 2.8; 95% CI, 0.6-13.0). In the triple-S (size, site, shape) prediction model, the 1-year risk of rupture ranged from 2.1% to 10.6%.
Within 1 year after growth detection, rupture occurred in approximately 1 of 25 aneurysms. The triple-S risk prediction model can be used to estimate absolute risk of rupture for the initial period after detection of growth.
Background and Purpose- Determinants for molecular and structural instability, that is, impending growth or rupture, of intracranial aneurysms (IAs) remain uncertain. To elucidate this, we endeavored ...to estimate the actual turnover rates of the main molecular constituent in human IA (collagen) on the basis of radiocarbon (
C) birth dating in relation to IA hemodynamics. Methods- Collagen turnover rates in excised human IA samples were calculated using mathematical modeling of
C birth dating data of collagen in relation to risk factors and histological markers for collagen maturity/turnover in selected IA. Hemodynamics were simulated using image-based computational fluid dynamics. Correlation, logistic regression, and receiver operating characteristic analyses were performed. Results- Collagen turnover rates were estimated in 46 IA (43 patients); computational fluid dynamics could be performed in 20 IA (20 patients). The mean collagen turnover rate (γ) constituted 126% (±1% error) per year. For patients with arterial hypertension, γ was greater than 2600% annually, whereas γ was distinctly lower with 32% (±1% error) per year for patients without risk factors, such as smoking and hypertension. There was a distinct association between histological presence of rather immature collagen in human IA and the presence of modifiable risk factors. Spatial-temporal averaged wall shear stress predicted rapid collagen turnover (odds ratio, 1.6 95% CI, 1.0-2.7). Receiver operating characteristic analysis demonstrated a good test accuracy (area under the curve, 0.798 95% CI, 0.598-0.998) for average wall shear stress with a threshold ≥4.9 Pa for rapid collagen turnover. Conclusions- Our data indicate that turnover rates and stability of collagen in human IA are strongly associated with the presence of modifiable risk factors and aneurysmal hemodynamics. These findings underline the importance of strict risk factor modification in patients with unruptured IA. Future should include more detailed risk factor data to establish a more causal understanding of hemodynamics and the rupture risk of individual IA.
Background and purpose
Aneurysmal subarachnoid hemorrhage (ASAH) is a complex disease with higher incidence in women compared to men and in Japan compared to other countries. It was hypothesized that ...ASAH is consistent with a multistep model of disease. The following assessments were made: (1) the number of steps needed for the disease to occur and (2) whether this number may be different in female versus male and in Japanese versus non‐Japanese patients.
Methods
Incidence data were generated from a meta‐analysis on ASAH incidence until 2017, which was supplemented with a literature search from 2017 to April 2023. Age‐ and sex‐adjusted incidences per 10‐year age groups were calculated and the logarithm of age‐specific incidence against the logarithm of age was regressed with least‐squares regression.
Results
In 2317 ASAH patients a linear relationship between logarithm of incidence and logarithm of age was found with a slope estimate of 3.13 (95% confidence interval 2.60–3.65), consistent with a four‐step process. Similar estimates were found for female, male, Japanese and non‐Japanese patients.
Conclusions
Our results suggest that ASAH is a four‐step process, also in subgroups with higher ASAH incidence. Elucidation of the exact nature of these steps can provide important clues for identification of disease mechanisms underlying ASAH.
Background
The appropriate management of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) remains uncertain. We aimed to evaluate the effect of implementing a ...standardized protocol for detection and management of DCI after aSAH on cerebral infarction and functional outcome.
Methods
We studied two cohorts of aSAH patients, one before (pre-implementation cohort: January 2012 to August 2014) and one after (post-implementation cohort: January 2016 to July 2018) implementation of a multidisciplinary approach, with standardized neurological and radiological assessment and risk-based medical treatment of DCI. We assessed the presence of new hypodensities on CT within 6 weeks after aSAH and categorized cerebral infarction into overall and DCI-related infarctions (hypodensities not within 48 h after IA repair and not attributable to aneurysm occlusion or intraparenchymal hematoma). Functional outcome was assessed at 3 months using the extended Glasgow outcome scale (eGOS), dichotomized into unfavorable (eGOS: 1–5) and favorable (eGOS: 6–8). We calculated odds ratios (OR) with corresponding 95% confidence intervals (CI’s), and adjusted for age, WFNS grade, Fisher score, and treatment modality (aOR).
Results
In the post-implementation (
n
= 158) versus the pre-implementation (
n
= 143) cohort the rates for overall cerebral infarction were 29.1% vs 46.9% (aOR: 0.41 0.24–0.69), for DCI-related cerebral infarction 17.7% vs. 31.5% (aOR: 0.41 0.23–0.76), and for unfavorable functional outcome at 3 months 37.3% vs. 53.8% (aOR: 0.30 0.17–0.54). For patients with DCI, the rates for unfavorable functional outcomes at 3 months in the post-implementation versus the pre-implementation cohort were 42.3% vs. 77.8% (aOR: 0.1 0.03–0.27).
Conclusions
A multidisciplinary approach with more frequent and standardized neurological assessment, standardized CT and CT perfusion monitoring, as well as tailored application of induced hypertension and invasive rescue therapy strategies, is associated with a significant reduction of cerebral infarction and unfavorable functional outcome after aneurysmal aSAH.
There is increasing interest in drug therapy for preventing aneurysmal subarachnoid hemorrhage (aSAH). We aimed to comprehensively evaluate the association between drug use and the risk of aSAH. We ...searched PubMed and Scopus from the databases’ inception until December 2021. Observational studies reporting the association between any drug therapy and aSAH were included. The odds ratios (ORs) for each drug used in aSAH were meta-analyzed with a random-effect model. According to the systematic review, 25 observational studies were eligible for the present study. Four therapeutic purpose-based classes (e.g., lipid-lowering agents) and 14 mechanism-based classes (e.g., statins) were meta-analyzed. Anti-hypertensive agents (OR, 0.50; 95% confidence interval 95% CI, 0.33–0.74), statins (OR, 0.55; 95% CI, 0.35–0.85), biguanides (OR, 0.57; 95% CI, 0.34–0.96), and acetylsalicylic acid (ASA) (OR, 0.62; 95% CI, 0.41–0.94) were inversely associated with the risk of aSAH. Non-ASA non-steroidal anti-inflammatory drugs (OR, 1.73; 95% CI, 1.07–2.79), selective cyclooxygenase-2 inhibitors (OR, 2.04; 95% CI, 1.24–3.35), vitamin K antagonists (OR, 1.50; 95% CI, 1.18–1.91), and dipyridamole (OR, 1.77; 95% CI, 1.23–2.54) were positively associated with the incidence of aSAH. There was also a trend toward a positive association between glucocorticoids (OR, 1.38; 95% CI, 0.97–1.94) and aSAH. The present study suggests that anti-hypertensive agents, statins, biguanides, and ASA are candidate drugs for preventing aSAH. By contrast, several drugs (e.g., anti-thrombotic drugs) may increase the risk of aSAH. Thus, the indications of these drugs in patients with intracranial aneurysms should be carefully determined.
This paper deals with comparative studies of bending behavior of untreated and modified European beech (Fagus sylvatica L.), European oak (Quercus spp.) and black locust (Robinia pseudoacacia L.). ...The modification of the woods included both ammonia treatment and ammonia treatment in combination with mechanical densification. For each ammonia treatment, pure gaseous ammonia was used. The investigations were conducted by means of three-point bending tests. The bulk density increases significantly due to ammonia treatment and, furthermore, due to additional mechanical densification. The modulus of rupture is not affected by ammonia treatment. Additional mechanical densification, however, leads to a strong increase in the strength and stiffness. The deflection behavior changes in such a way that the ammonia treatment leads to an increase in deflection, and the additional mechanical densification further reinforces this trend.
Background
Decompressive craniectomy (DC) can alleviate increased intracranial pressure in aneurysmal subarachnoid hemorrhage patients with concomitant space-occupying intracerebral hemorrhage, but ...also carries a high risk for complications. We studied outcomes and complications of DC at time of ruptured aneurysm repair.
Methods
Of 47 patients treated between 2010 and 2020, 30 underwent DC during aneurysm repair and hematoma evacuation and 17 did not. We calculated odds ratios (OR) for delayed cerebral ischemia (DCI), angiographic vasospasm, DCI-related infarction, and unfavorable functional outcome (extended Glasgow Outcome Scale 1–5) at three months. Complication rates after DC and cranioplasty in the aneurysmal subarachnoid hemorrhage patients were compared to those of all 107 patients undergoing DC for malignant cerebral infarction during the same period.
Results
In DC versus no DC patients, proportions were for clinical DCI 37% versus 53% (OR = 0.5;95%CI:0.2–1.8), angiographic vasospasm 37% versus 47% (OR = 0.7;95%CI:0.2–2.2), DCI-related infarctions 17% versus 47% (OR = 0.2;95%CI:0.1–0.7) and unfavorable outcome 80% versus 88% (OR = 0.5;95%CI:0.1–3.0). ORs were similar after adjustment for baseline predictors for outcome. Complications related to DC and cranioplasty occurred in 18 (51%) of subarachnoid hemorrhage patients and 41 (38%) of cerebral infarction patients (OR = 1.7;95%CI:0.8–3.7).
Conclusions
In patients with aneurysmal subarachnoid hemorrhage and concomitant space-occupying intracerebral hemorrhage, early DC was not associated with improved functional outcomes, but with a reduced rate of DCI-related infarctions. This potential benefit has to be weighed against high complication rates of DC in subarachnoid hemorrhage patients.
Abstract Objective Spontaneous cerebellar hemorrhages (SCH) can lead to life-threatening complications with high mortality rates of 20-50%. Although complications of SCH can be prevented by surgical ...therapy, there is a lack of consensus concerning the optimal surgical technique for evacuating SCH. Methods In this retrospective study 85 patients with SCH were divided into four treatment groups: 1. Decompression and Hematoma Evacuation via suboccipital craniectomy and removal of the posterior arch of C1 (DHE), 2. Hematoma Evacuation Only via craniotomy (HEO), 3. External Ventricular Drainage (EVD), 4. Conservative treatment (C). To ascertain the level of consciousness, Glasgow Coma Scale (GCS) was calculated. To evaluate the clinical and neurological outcome, modified Rankin Score, Glasgow Outcome Scale and mortality rate were recorded after six months. Results The mean volume of hematoma was significant larger in the DHE- and HEO-group compared to the EVD- and C-group before treatment. DHE and HEO could significantly reduce the volume comparing pre- and postoperative measurements. Larger preoperative volume was a strong predictor of worse neurological outcome and high mortality. Overall mortality was 25.9%. After subdivision into the treatment groups, a comparison of the DHE- and HEO-groups showed a trend towards lower mortality and better neurological outcome in the DHE-group. Patients with the worst preoperative GCS scores profited significantly from DHE with respect to regaining consciousness. Conclusions Patients with SCH should receive surgical therapy when hemorrhages are space-occupying and when the patient's neurological condition deteriorates. With regards to surgical technique, and limited by the retrospective design of the study, our results indicate that patients might benefit most from DHE.
Introduction
Variability in usage and definition of data characteristics in previous cohort studies on unruptured intracranial aneurysms (UIA) complicated pooling and proper interpretation of these ...data. The aim of the National Institute of Health/National Institute of Neurological Disorders and Stroke UIA and Subarachnoid Hemorrhage (SAH) Common Data Elements (CDE) Project was to provide a common structure for data collection in future research on UIA and SAH.
Methods
This paper describes the development and summarization of the recommendations of the working groups (WGs) on UIAs, which consisted of an international and multidisciplinary panel of cerebrovascular specialists on research and treatment of UIAs. Consensus recommendations were developed by review of previously published CDEs for other neurological diseases and the literature on UIAs. Recommendations for CDEs were classified by priority into ‘Core,’ ‘Supplemental—Highly Recommended,’ ‘Supplemental,’ and ‘Exploratory.’
Results
Ninety-one CDEs were compiled; 69 were newly created and 22 were existing CDEs. The CDEs were assigned to eight subcategories and were classified as Core (8), Supplemental—Highly Recommended (23), Supplemental (25), and Exploratory (35) elements. Additionally, the WG developed and agreed on a classification for aneurysm morphology.
Conclusion
The proposed CDEs have been distilled from a broad pool of characteristics, measures, or outcomes. The usage of these CDEs will facilitate pooling of data from cohort studies or clinical trials on patients with UIAs.
Prediction of intracranial aneurysm growth risk can assist physicians in planning of follow-up imaging of conservatively managed unruptured intracranial aneurysms. We therefore aimed to externally ...validate the ELAPSS (Earlier subarachnoid hemorrhage, aneurysm Location, Age, Population, aneurysm Size and Shape) score for prediction of the risk of unruptured intracranial aneurysm growth.
From 11 international cohorts of patients ≥18 years with ≥1 unruptured intracranial aneurysm and ≥6 months of radiological follow-up, we collected data on the predictors of the ELAPSS score, and calculated 3- and 5-year absolute growth risks according to the score. Model performance was assessed in terms of calibration (predicted versus observed risk) and discrimination (c-statistic).
We included 1,072 patients with a total of 1,452 aneurysms. During 4,268 aneurysm-years of follow-up, 199 (14%) aneurysms enlarged. Calibration was comparable to that of the development cohort with the overall observed risks within the range of the expected risks. The c-statistic was 0.69 (95% confidence interval CI, 0.64 to 0.73) at 3 years, compared to 0.72 (95% CI, 0.68 to 0.76) in the development cohort. At 5 years, the c-statistic was 0.68 (95% CI, 0.64 to 0.72), compared to 0.72 (95% CI, 0.68 to 0.75) in the development cohort.
s The ELAPSS score showed accurate calibration for 3- and 5-year risks of aneurysm growth and modest discrimination in our external validation cohort. This indicates that the score is externally valid and could assist patients and physicians in predicting growth of unruptured intracranial aneurysms and plan follow-up imaging accordingly.
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