Atorvastatin and growth, rupture of small unruptured intracranial aneurysm: results of a prospective cohort study

Role of inflammatory mediators in intracranial aneurysms: A review

The formation, growth, and rupture of intracranial aneurysms (IAs) involve hemodynamics, blood pressure, external stimuli, and a series of hormonal changes. In addition, inflammatory response causes the release of a series of inflammatory mediators, such as IL, TNF-α, MCP-1, and MMPs, which directly or indirectly promote the development process of IA. However, the specific role of these inflammatory mediators in the pathophysiological process of IA remains unclear. Recently, several anti-inflammatory, lipid-lowering, hormone-regulating drugs have been found to have a potentially protective effect on reducing IA formation and rupture in the population. These therapeutic mechanisms have not been fully elucidated, but we can look for potential therapeutic targets that may interfere with the formation and breakdown of IA by studying the relevant inflammatory response and the mechanism of IA formation and rupture involved in inflammatory mediators.

Risk factors for the rupture of intracranial aneurysms: a systematic review and meta-analysis

Purpose

The study aimed to identify potential risk factors for aneurysm rupture by performing a systematic review and meta-analysis.

Materials and methods

We systematically searched the PubMed, Embase, and Cochrane Library electronic databases for eligible studies from their inception until June 2023.

Results

Eighteen studies involving 17,069 patients with unruptured intracranial aneurysm (UIA) and 2,699 aneurysm ruptures were selected for the meta-analysis. Hyperlipidemia [odds ratio (OR): 0.47; 95% confidence interval (CI): 0.39-0.56; p < 0.001] and a family history of subarachnoid hemorrhage (SAH) (OR: 0.81; 95% CI: 0.71-0.91; p = 0.001) were associated with a reduced risk of aneurysm rupture. In contrast, a large-size aneurysm (OR: 4.49; 95% CI: 2.46-8.17; p < 0.001), ACA (OR: 3.34; 95% CI: 1.94-5.76; p < 0.001), MCA (OR: 2.16; 95% CI: 1.73-2.69; p < 0.001), and VABA (OR: 2.20; 95% CI: 1.24-3.91; p = 0.007) were associated with an increased risk of aneurysm rupture. Furthermore, the risk of aneurysm rupture was not affected by age, sex, current smoking, hypertension, diabetes mellitus, a history of SAH, and multiple aneurysms.

Conclusion

This study identified the predictors of aneurysm rupture in patients with UIAs, including hyperlipidemia, a family history of SAH, a large-size aneurysm, ACA, MCA, and VABA; patients at high risk for aneurysm rupture should be carefully monitored.

Systematic Review Registration

Our study was registered in the INPLASY platform (INPLASY202360062).

Clinical, 3D Morphological, and Hemodynamic Risk Factors for Instability of Unruptured Intracranial Aneurysms

PURPOSE

Neurosurgeons can manage unruptured intracranial aneurysms (UIAs). However, the stability of UIAs under follow-up remains uncertain. This study aimed to examine the risk factors associated with the instability (rupture or growth) of UIAs during follow-up.

METHODS

We obtained information on patients with UIA who underwent ≥ 6 months of the time of flight-magnetic resonance angiography (TOF-MRA) imaging follow-up in two centers. Computer-assisted semi-automated measurement (CASAM) techniques were used for recording morphological parameters and determining the growth of these aneurysms. We also recorded hemodynamic parameters at the beginning of the follow-up. The univariate and multivariate Cox regression analyses were performed to calculate hazard ratios with corresponding 95% confidence intervals for the clinical, morphological, and hemodynamic risk factors for aneurysm instability.

RESULTS

A total of 304 aneurysms from 263 patients (80.4%) were included for analysis. The annual aneurysm growth rate was 4.7%. Significant predictive factors for aneurysm instability in the multivariate analysis were as follows: poorly controlled hypertension (hazard ratio (HR), 2.97 (95% CI, 1.27-6.98), P = 0.012); aneurysms located on posterior circulation (HR, 7.81 (95% CI, 2.28-26.73), P = 0.001), posterior communication artery (HR, 3.01 (95% CI, 1.07-8.46), P = 0.036), and cavernous carotid artery (HR, 3.78 (95% CI, 1.18-12.17), P = 0.026); and size ratio ≥ 0.87 (HR, 2.54 (95% CI, 1.14-5.68), P = 0.023).

CONCLUSIONS

The management of UIAs should focus on the control of hypertension during the follow-up. Aneurysms on the posterior communicating artery, posterior circulation, and cavernous carotid arteries require intensive surveillance or timely treatment.

Intracranial Aneurysms and Lipid Metabolism Disorders: From Molecular Mechanisms to Clinical Implications

Many vascular diseases are linked to lipid metabolism disorders, which cause lipid accumulation and peroxidation in the vascular wall. These processes lead to degenerative changes in the vessel, such as phenotypic transformation of smooth muscle cells and dysfunction and apoptosis of endothelial cells. In intracranial aneurysms, the coexistence of lipid plaques is often observed, indicating localized lipid metabolism disorders. These disorders may impair the function of the vascular wall or result from it. We summarize the literature on the relationship between lipid metabolism disorders and intracranial aneurysms below.

Surgical Clipping of Intracranial Aneurysms Using a Transcranial Neuroendoscopic Approach

OBJECTIVE

This retrospective study was performed to evaluate the feasibility and safety of surgically clipping intracranial aneurysms using a transcranial neuroendoscopic approach.

METHODS

A total of 229 patients with cerebral aneurysms were included in our study, all of whom were treated with clamping surgery at Wuhan University People's Hospital. They were divided into neuroendoscopic and microscopic groups, according to whether or not neuroendoscopy was used for the clamping surgery. We statistically analyzed the patients' baseline data, surgical outcomes, and complications, which were then evaluated to assess the treatment effect.

RESULTS

The baseline characteristics were not statistically significant, except for gender, for which the proportions of female patients in the two groups were 69 (56.1%) and 46 (43.4%). There were no patients with incomplete aneurysm clamping or parent vessel occlusion in the neuroendoscopic group, and there were 4 (3.8%) and 2 (1.9%) in the microscopic group, respectively; however, there was no statistically significant difference in the comparison of the two groups. The mean operative times of the two groups were 181 min and 154 min, respectively, and were statistically different. However, the mRS scores of the two groups showed no significant difference in patient prognosis. The differences in complications (including limb hemiplegia, hydrocephalus, vision loss, and intracranial infection) were not statistically significant, except for cerebral ischemia, for which the proportions of patients in the two groups were 8 (6.5%) and 16 (15.1%).

CONCLUSIONS

Neuroendoscopy can provide clear visualization and multi-angle views during aneurysm clipping, which is helpful for ensuring adequate clipping and preventing complications.

Potential application of peripheral blood biomarkers in intracranial aneurysms

Intracranial aneurysm (IA) counts are increasing yearly, with a high mortality and disability after rupture. Current diagnosis and treatment rely on costly equipment, lacking effective indicators for progression prediction and specific drugs for treatment. Recently, peripheral blood biomarkers, as common clinical test samples, reflecting the immune and inflammatory state of the body in real-time, have shown promise in providing additional information for risk stratification and treatment in IA patients, which may improve their outcomes after aneurysm rupture through anti-inflammatory therapy. Therefore, this paper reviewed the progress of potential biomarkers of IAs, including inflammatory blood indicators, cytokines, and blood lipids, aiming to aid individual management and therapy of aneurysms in clinical practices.

Statins may Decrease Aneurysm wall Enhancement of Unruptured Fusiform Intracranial Aneurysms: A high-resolution 3T MRI Study

Inflammation plays an integral role in the formation, growth, and progression to rupture of unruptured intracranial aneurysms. Aneurysm wall enhancement (AWE) in high-resolution magnetic resonance imaging (HR-MRI) has emerged as a surrogate biomarker of vessel wall inflammation and unruptured intracranial aneurysm instability. We investigated the correlation between anti-inflammatory drug use and three-dimensional AWE of fusiform intracranial aneurysms (FIAs). We retrospectively analyzed consecutive patients with FIAs in our database who underwent 3T HR-MRI at three Chinese centers. FIAs were classified as fusiform-type, dolichoectatic-type, or transitional-type. AWE was objectively defined using the aneurysm-to-pituitary stalk contrast ratio in three-dimensional space by determining the contrast ratio of the average signal intensity in the aneurysmal wall and pituitary stalk on post-contrast T1-weighted images. Data on aneurysm size, morphology, and location, as well as patient demographics and comorbidities, were collected. Univariate and multivariate logistic regression analyses were performed to determine factors independently associated with AWE of FIAs on HR-MRI. In total, 127 FIAs were included. In multivariate analysis, statin use (β = -0.236, P = 0.007) was the only independent factor significantly associated with decreased AWE. In the analysis of three FIA subtypes, the fusiform and transitional types were significantly associated with statin use (rs = -0.230, P = 0.035; and rs = -0.551, P = 0.010; respectively). It establishes an incidental correlation between the use of statins daily for ≥ 6 months and decreased AWE of FIAs. The findings also indicate that the pathophysiology may differ among the three FIA subtypes.

Aneurysm wall enhancement, atherosclerotic proteins, and aneurysm size may be related in unruptured intracranial fusiform aneurysms

OBJECTIVE

This cross-sectional study aimed to investigate the associations between aneurysm wall enhancement (AWE), atherosclerotic protein levels, and aneurysm size in unruptured intracranial fusiform aneurysms (IFAs).

METHODS

Patients with IFAs underwent high-resolution magnetic resonance imaging (HR-MRI) and atherosclerotic protein examinations from May 2015 to December 2021 were collected. A CR_stalk (signal intensity [SI] of IFA wall/SI of pituitary stalk) > 0.60 was considered to indicate AWE. Atherosclerotic protein data was obtained from the peripheral blood. Aneurysmal characteristics included the maximal diameter of the cross-section (D_max), location, type of IFA, presence of mural thrombus, and mural clots. Statistical analyses were performed with univariate analysis, logistic regression analysis, and Spearman's correlation coefficient.

RESULTS

Seventy-one IFAs from 71 patients were included in the study. Multivariate analysis revealed statin use (OR = 0.189, p = 0.026) and apolipoprotein B (Apo-B) level (OR = 6.019, p = 0.026) were the independent predictors of AWE in IFAs. In addition, statin use (OR = 0.813, p = 0.036) and Apo-B level (OR = 1.610, p = 0.003) were also the independent predictors of CR_stalk. Additionally, we found that CR_stalk and AWE were significantly positively associated with D_max (r_s = 0.409 and 0.349, respectively; p < 0.001 and p = 0.003, respectively).

CONCLUSIONS

There may be correlations between AWE, atherosclerotic protein levels, and aneurysm size in patients with IFAs. Apo-B and statin use were independent predictors of AWE in IFAs, which have the potential to be new therapeutic targets for IFAs.

KEY POINTS

• There may be correlations between aneurysm wall enhancement, atherosclerotic protein levels in the peripheral blood, and aneurysm size in patients with intracranial fusiform aneurysms. • Apolipoprotein B and statin use were independent predictors of aneurysm wall enhancement in intracranial fusiform aneurysms.

Homocysteine Levels Are Associated With the Rupture of Intracranial Aneurysms

Background

Homocysteine (Hcy) levels may be associated with the development of intracranial aneurysms (IAs). However, whether it increases the risk of rupture of IAs is unknown. This study aimed to determine the association between homocysteine levels and IA rupture.

Methods

We retrospectively reviewed patients with IAs and subarachnoid hemorrhage (SAH) at our hospital between January 2019 and May 2021. Clinical data, including Hcy levels and IA images, were assessed. The association between Hcy level and IA rupture was investigated using multivariate logistic regression analyses in patients with IAs and SAH.

Results

A total of 589 patients were included. 546 patients with IAs, including 331 UIA (Unruptured IA) and 215 RIA (Ruptured IA). The average age was 57.43 ± 10.86 years old, and 67.03% were women. Among them, all 215 RIAs lead to SAH. In addition, we also enrolled 43 non-aneurysmal subarachnoid hemorrhage (Na-SAH) patients. The average age was 54.12 ± 10.55 years old, and 53.48% were female. After adjusting for confounders in the multivariate model, Hcy levels were correlated with the rupture of IA (odds ratio [OR] 1.069; 95% confidence interval [CI] 1.025–1.114, p = 0.002) and a-SAH (OR 1.083; 95% CI 1.002–1.170, p = 0.046).

Conclusion

Hcy levels were associated with IA rupture. These findings provide novel insights into IAs rupture, and future studies are needed to confirm this relationship.

Effect of Renin-Angiotensin-Aldosterone System Inhibitors on the Rupture Risk Among Hypertensive Patients With Intracranial Aneurysms

BACKGROUND

Mounting experimental evidence supports the concept that the RAAS (renin-angiotensin-aldosterone system) is involved in the pathogenesis of intracranial aneurysm rupture. However, whether RAAS inhibitors could reduce the rupture risk of intracranial aneurysms remains unclear.

METHODS

We performed a chart review of a multicenter, prospectively maintained database of 3044 hypertensive patients with intracranial aneurysms from 20 medical centers in China. The patients were separated into ruptured and unruptured groups. Univariable and multivariable logistical regression analyses were performed to determine the association between the use of RAAS inhibitors and the rupture risk. Sensitivity analyses and subgroup analyses were performed to verify the robustness of the results.

RESULTS

In multivariable analyses, female sex, passive smoking, uncontrolled, or unmonitored hypertension, use of over 2 antihypertensive medications, RAAS inhibitors use, antihyperglycemic agents use, hyperlipidemia, ischemic stroke, and aneurysmal location were independently associated with the rupture risk. The use of RAAS inhibitors was significantly associated with a reduced rupture risk compared with the use of non-RAAS inhibitors (odds ratio, 0.490 [95% CI, 0.402-0.597]; P=0.000). Compared with the use of non-RAAS inhibitors, the use of ACE (angiotensin-converting enzyme) inhibitors (odds ratio, 0.559 [95% CI, 0.442-0.709]; P=0.000) and use of ARBs (angiotensin receptor blockers; odds ratio, 0.414 [95% CI, 0.315-0.542]; P=0.000) were both significantly associated with a reduced rupture risk. The negative association of the rupture risk with RAAS inhibitors was consistent across 3 analyzed data and the predefined subgroups (including controlled hypertension).

CONCLUSIONS

The use of RAAS inhibitors was significantly associated with a decreased rupture risk independent of blood pressure control among hypertensive patients with intracranial aneurysms.

Effects of blood lipids and lipid-modifying drugs on intracranial aneurysms

OBJECTIVES

We used 2-sample Mendelian randomization (MR) to examine the effects of blood lipids and lipid-modifying drugs on intracranial aneurysm (IA).

METHODS

Genetic variants for the effects of high-density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (apo-A1), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (apo-B), and triglycerides and targets for lipid-modifying drugs were selected from the genome-wide discovery analyses of the UK Biobank. Summary-level data on IAs were obtained from the International Stroke Genetics Consortium (ISGC). Univariate and multivariate MR analyses were performed.

RESULTS

Univariate MR analyses showed that the HDL-C was negatively correlated with IA (OR, 0.816; 95% CI, 0.715-0.932; P=0.003) and ruptured IA (rIA) (OR, 0.775, 0.663-0.906; P=0.001). The MVMR-IVW analysis showed that the HDL-C was negatively correlated with IA (OR, 0.655; 95% CI, 0.434-0.988; P=0.043) and rIA (OR, 0.563, 0.347-0.913; P=0.02), and the LDL-C was negatively correlated with IA (OR, 0.402; 95% CI, 0.191-0.848; P=0.017) and rIA (OR, 0.376, 0.160-0.883; P=0.025). Using genetic proxies of known lipid-modifying drugs, we found that the increased HDL-C with CETP proxies was associated with a decreased risk of rIA (OR, 0.852, 0.747-0.973; P=0.018), and the decreased LDL-C with HMGCR proxies were associated with increased risk of IA (OR, 1.772; 95% CI, 1.080-2.908; P=0.024) and rIA (OR, 1.856; 95% CI, 1.022-3.371; P = 0.042).

CONCLUSIONS

Genetically determined HDL-C and LDL-C reduce the risk of IA and rIA. The effects of different lipid-modifying drugs on IA need to be further investigated.

Case Report: The Different Fates of Three Aneurysms: Diagnosis and Treatment Strategies for Unruptured Intracranial Aneurysms With Other Intracranial Diseases

Intracranial aneurysms are vascular diseases characterized by local aneurysms of intracranial arteries. Their etiology involves a variety of environmental and genetic factors. Unruptured intracranial aneurysms (UIAs) are more common in intracranial aneurysms, but once an aneurysm is ruptured, the fatality rate and disability rate are extremely high. Therefore, accurate assessment of each step in the detection of intracranial aneurysms, assessment of the risk of rupture, formulation of treatment strategies, and treatment benefits will help to better treat the disease. At present, the treatment of intracranial aneurysms is limited. Except for surgical intervention, there are no other effective methods. Therefore, when a patient has a UIA, the formulation of treatment and management strategies is a difficult issue facing neurosurgery. This article introduces the choice of different treatment strategies for 3 patients with intracranial aneurysms complicated with other diseases and reviews the literature.

Atorvastatin for unruptured intracranial vertebrobasilar dissecting aneurysm (ATREAT-VBD): protocol for a randomised, double-blind, blank-controlled trial

INTRODUCTION

Vertebrobasilar dissecting aneurysms (VBDAs) are associated with serious complications and a poor prognosis. It is believed that inflammation of the aneurysm wall may be the main cause of rupture or deterioration. Atorvastatin has been shown to inhibit inflammation and may be a suitable drug candidate. Here, we report a clinical research study protocol to investigate whether atorvastatin inhibits inflammation of the aneurysm wall, as measured by signal index enhancement.

METHODS AND ANALYSIS

We have designed a single-centre, randomised, double-blind, blank-controlled clinical trial. 40 patients with non-ruptured VBDAs with enhancement aneurysm walls will be enrolled in Beijing Tiantan Hospital. Eligible patients will be randomly divided into two treatment groups, at a ratio of 1:1, to receive atorvastatin 20 mg orally for 6 months or no treatment. The primary assessment outcome will be the change in aneurysm wall enhancement, as measured by the signal index during the 6-month treatment period. The secondary assessment outcomes will be the aneurysm morphology (intramural haematoma, dissection valve and false lumen) and changes in the concentrations of inflammatory factors, including C reactive protein, tumour necrosis factor-α, interleukin (IL)-1β and IL-6.

ETHICS AND DISSEMINATION

The protocol has been approved by the medical ethics committee of the Beijing Tiantan Hospital at which the work will be conducted (Approval No. KY 2019-024-02). Written informed consent will be obtained from all participants. Findings from the study will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04943783.

Incidental intracranial saccular aneurysm in a patient with post-Covid-19 headache: What to do with the incidentaloma?

Case report