Risk Factors for the Rupture of Intracranial Aneurysms Using Computed Tomography Angiography

Assessment of balloon remodeling techniques in endovascular treatment of wide-neck intracranial aneurysms (WN-IAs)

OBJECTIVES

To evaluate the clinical, technical, and angiographic results in endovascular management of wide-neck intracranial aneurysms (WN-IAs) using the balloon-remodeling technique.

METHODS

This study was a prospective, single-center study that was carried out over a period of three years from January 2019 to December 2021 at the Neuro-Interventional Unit at our hospital. Patients who presented with WNIAs and were eligible for endovascular treatment using the balloon-remodeling approach were included in the study.

RESULTS

We included 37 patients with a mean age of 49.7 ± 12.3 years. About 91.9% of the participants had SAH, 5.4% had unruptured aneurysms, and 2.7% had intracranial hemorrhage. The mean time to treatment was 6.97 ± 7.35 days, the mean aneurysm diameter was 5.7 ± 1.7 mm, and the mean neck diameter was 3.8 ± 1.0 mm. The majority of the patients had a dom-to-neck ratio of less than 2 (89.2%). We have used hyper form balloons in 48.6%, hyper glide in 43.2%, Copernic balloons in 5.4%, and eclipse in 2.7%. According to the Raymond-Roy occlusion classification, 86.5% of the patients had complete obliteration, 10.8% had residual neck, and 2.7% had a residual aneurysm. Almost 91.9% had no complications, 2.7% had ischemia, and 5.4% had mild rupture by wire, treated by 5 min hyperinflation of the balloon till hemorrhage stopped.

CONCLUSIONS

Balloon-assisted detachable coiling is an important option in the treatment of WN-IAs. We found that this technique allowed safe and efficient treatment of aneurysms when conventional treatment had failed due to WN. Endovascular coiling using the balloon remodeling technique of wide neck showed a high technical success rate and good short-term clinical outcomes. A good selection of patients with WN-IAs treated by endovascular coiling using balloon remodeling technique and a good selection of materials used help in decreasing the complications.

Identification of ruptured intracranial aneurysms using the aneurysm-specific prediction score in patients with multiple aneurysms with subarachnoid hemorrhages- a Chinese population based external validation study

Background

For patients with aneurysmal subarachnoid hemorrhages (SAHs) and multiple intracranial aneurysms (MIAs), a simple and fast imaging method that can identify ruptured intracranial aneurysms (RIAs) may have great clinical value. We sought to use the aneurysm-specific prediction score to identify RIAs in patients with MIAs and evaluate the aneurysm-specific prediction score.

Methods

Between May 2018 and May 2021, 134 patients with 290 MIAs were retrospectively analyzed. All patients had an SAH due to IA rupture. CT angiography (CTA) was used to assess the maximum diameter, shape, and location of IAs to calculate the aneurysm-specific prediction score. Then, the aneurysm-specific prediction score was applied to RIAs in patients with MIAs.

Results

The IAs with the highest aneurysm-specific prediction scores had not ruptured in 17 (12.7%) of the 134 patients with 290 MIAs. The sensitivity, specificity, false omission rate, diagnostic error rate, and diagnostic accuracy of the aneurysm-specific prediction score were higher than those of the maximum diameter, shape, and location of IAs.

Conclusions

The present study suggests that the aneurysm-specific prediction score has high diagnostic accuracy in identifying RIAs in patients with MIAs and SAH, but that it needs further evaluation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02727-w.

Risk factors for the progression of unruptured intracranial aneurysms in patients followed by CT/MR angiography

Background

The progression of an unruptured intracranial aneurysm (UIA) is associated with a higher rupture risk. The aim of this study was to identify the risk factors for the progression of UIAs among Chinese adults and compare them with the ELAPSS (Earlier subarachnoid hemorrhage, IA Location, Age, Population, IA Size and Shape) score.

Methods

Four hundred thirty-eight consecutive patients with 491 UIAs were followed and reviewed retrospectively from August 2011 to November 2019. Follow-up images of the UIAs were used to determine changes in IA size and shape. Patients and IAs were divided into non-progression and progression groups. In addition to the clinical characteristics of the patients, the features of the IAs (e.g., size and shape) were evaluated by computed tomography angiography (CTA) or magnetic resonance angiography (MRA). Independent risk factors for UIA progression were studied using multiple Cox proportional hazards regression analysis. In addition, the diagnostic value of the ELAPSS score for the prediction of UIA progression was calculated.

Results

Seventy-two IAs in 68 patients progressed during a mean follow-up time of 24.2±19.68 months. IAs located at the bifurcation [odds ratio (OR) 2.600], with an irregular shape (OR 2.981) or having a high aspect ratio (AR, OR 2.430) were correlated with progression. Based on these three factors, the threshold value of our predictive score was 0.5, and the area under the curve (AUC), sensitivity and specificity were 0.756, 93.1% and 40.6%, respectively, while the AUC, sensitivity and specificity of the ELAPSS score were 0.711, 55.6%, and 75.2%, respectively.

Conclusions

IAs located at the bifurcation, with an irregular shape and with an elevated AR are risk factors for UIA progression in the Chinese population. Our predictive score is of great value in predicting the risk of UIA progression.

Risk of Rupture of Small Intracranial Aneurysms (≤5 mm) Among the Chinese Population

OBJECTIVE

We sought to develop a model to predict the risk of small intracranial aneurysm (SIA; ≤5 mm) rupture among Chinese adults and to compare the score predicted by our model with the PHASES (population, hypertension, age, size, earlier subarachnoid hemorrhage, aneurysm site) score.

METHODS

From August 2011 to June 2015, 366 patients with 394 SIAs were retrospectively evaluated and followed up for ≥5 years. The clinical characteristics of the patients were reviewed from their medical records, and the SIA features were evaluated from the imaging studies. The independent risk factors for SIA rupture were studied using multiple Cox proportional hazards regression analysis. The diagnostic value of the PHASES score for the prediction of SIA rupture was also calculated.

RESULTS

Six SIAs in 6 different patients had ruptured during a mean follow-up of 6.4 years. An irregular shape (odds ratio [OR], 31.464), a high aspect ratio (OR, 40.573), and a high size ratio (OR, 20.541) increased the risk of rupture. The predictive score incorporated these three factors. The threshold was 1.5, and the area under the curve, sensitivity, and specificity were 0.986, 100%, and 94.6%, respectively. For the PHASES score, the area under the curve, sensitivity, and specificity were 0.702, 83.3%, and 62.1%, respectively.

CONCLUSIONS

An irregular shape, a high aspect ratio, and a high size ratio were associated with SIA rupture in the Chinese population. Our predictive score is of great value in predicting the risk of SIA rupture.

Size of ruptured intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND

There is wide variation in the reported size of ruptured intracranial aneurysms and methods of size estimation. There is widespread belief that small aneurysms < 7 mm do not rupture. Therefore, we performed a systematic review and meta-analysis of the literature to determine the size of ruptured aneurysms according to aneurysm locations and methods of size estimation.

METHODS

We searched PubMed, Cochrane, CINAHL, and EMBASE databases using a combination of Medical Subject Headings (MeSH) terms. We included articles that reported mean aneurysm size in consecutive series of ruptured intracranial. We excluded studies limited to a specific aneurysm location or type. The random-effects model was used to calculate overall mean size and location-specific mean size. We performed meta-regression to explain observed heterogeneity and variation in reported size.

RESULTS

The systematic review included 36 studies and 12,609 ruptured intracranial aneurysms. Overall mean aneurysm size was 7.0 mm (95% confidence interval [CI 6.2-7.4]). Pooled mean size varied with location. Overall mean size of 2145 ruptured anterior circulation aneurysms was 6.0 mm (95% CI 5.6-6.4, residual I² = 86%). Overall mean size of 743 ruptured posterior circulation aneurysms was 6.2 mm (95% CI 5.3-7.0, residual I² = 93%). Meta-regression identified aneurysm location and definition of size (i.e., maximum dimension vs. aneurysm height) as significant determinants of aneurysm size reported in the studies.

CONCLUSIONS

The mean size of ruptured aneurysms in most studies was approximately 7 mm. The general wisdom that aneurysms of this size do not rupture is incorrect. Location and size definition were significant determinants of aneurysm size.

Rupture Risk of Small Unruptured Intracranial Aneurysms in Japanese Adults

Background and Purpose—

Therapeutic decision making for small unruptured intracranial aneurysms (<10 mm) is difficult. We aimed to develop a rupture risk model for small intracranial aneurysms in Japanese adults, including clinical, morphological, and hemodynamic parameters.

Methods—

We analyzed 338 small unruptured aneurysms; 35 ruptured during the observation period, and 303 remained stable. Clinical, morphological, and hemodynamic parameters were considered. Computational fluid dynamics was used to calculate hemodynamic parameters based on computed tomography images of all aneurysms in their unruptured state. Differences between the ruptured and unruptured groups were tested by the Mann-Whitney U or Fisher exact tests. Multivariate logistic regression was applied to obtain a rupture risk model. Its predictive ability was investigated by receiver operating characteristic analysis.

Results—

The risk model revealed that rupture may be more likely to in younger patients (odds ratio [OR], 0.92 for each age increase of 1 year [95% CI, 0.88−0.96] P <0.001) with multiple aneurysms (OR, 2.58 [95% CI, 1.07−6.19] P =0.03), located at a bifurcation (OR, 5.45 [95% CI, 1.87−15.85] P =0.002), with a bleb (OR, 4.09 [95% CI, 1.42−11.79] P =0.009), larger length (OR, 1.91 for each increase of 1 mm [95% CI, 1.42−2.57] P <0.001), and lower pressure loss coefficient (OR, 0.33 for each decrease of 1 unit [95% CI, 0.14−0.77] P =0.01). The sensitivity, specificity, and area under the curve were 0.800, 0.752, and 0.826 (95% CI, 0.739−0.914) respectively.

Conclusions—

Younger age, presence of multiple aneurysms, location at a bifurcation, presence of a bleb, larger length, and lower pressure loss coefficient were identified as risk factors for rupture of small intracranial aneurysms. The risk model should be validated in further studies.

A Simple Scoring Model for Prediction of Rupture Risk of Anterior Communicating Artery Aneurysms

Background: The rupture risk of anterior communicating artery aneurysms (ACoAAs) has been known to be higher than that of aneurysms at other locations. Thus, the aim of this study is to investigate the clinical and morphological characteristics associated with risk factors for the rupture of ACoAAs.

Methods: In total, 361 consecutive patients with 361 ACoAAs between August 2011 and December 2017 were retrospectively reviewed. Patients and ACoAAs were divided into ruptured and unruptured groups. In addition to clinical characteristics, ACoAA characteristics were evaluated by CT angiography (CTA). A multiple logistic regression analysis was used to identify the independent risk factors associated with ACoAA rupture. The assignment score of these variables depends on the β coefficient. A receiver operating characteristic (ROC) curve analysis was used to calculate the optimal thresholds.

Results: The multiple logistic regression model revealed that A1 dominance [odds ratio (OR) 3.034], an irregular shape (OR 3.358), and an aspect ratio ≥1.19 (AR; OR 3.163) increased the risk of rupture, while cerebral atherosclerosis (OR 0.080), and mean diameters ≥2.48 mm (OR 0.474) were negatively correlated with ACoAA rupture. Incorporating these five factors, the ROC analysis revealed that the threshold value of the multifactors was one, the sensitivity was 88.3%, and the specificity was 66.0%.

Conclusions: The scoring model is a simple method that is based on A1 dominance, irregular shape, aspect ratio, cerebral atherosclerosis, and mean diameters from CTA and is of great value in the prediction of the rupture risk of ACoAAs.

Follow-Up and Treatment of Patients with Coexisting Brain Tumor and Intracranial Aneurysm

OBJECTIVE

The association of primary brain tumors with coexisting unruptured intracranial aneurysms (UIAs) has been debated, and treatment strategies have not yet been established. We evaluated the flow association between brain tumors and coexisting UIAs and the outcomes of patients with brain tumor who did not receive treatment of coexisting UIAs.

METHODS

The medical records of patients with coexisting UIAs and brain tumors who had undergone surgical tumor resection were retrospectively analyzed to evaluate the incidence of UIAs according to tumor type, association of arterial feeder vessels and coexisting UIAs, and the occurrence of subarachnoid hemorrhage during the follow-up period for patients who had not receive treatment for the UIAs.

RESULTS

Of the 55 patients, 21 (38.9%) had undergone treatment of UIAs and 33 (61.1%) had received regular follow-up examinations without UIA treatment. Two patients (6.1%) developed subarachnoid hemorrhage. Of the 33 patients with astrocytic or oligodendroglial tumors who had not undergone treatment of UIAs, 2 had experienced an interval increase. Flow-related UIAs were found to be significantly more common in patients with astrocytic or oligodendroglial tumors than in those with tumors of other histological types (P = 0.01).

CONCLUSIONS

The incidence of UIAs among patients with primary brain tumors appears to be greater than that in the general population. An interval increase in aneurysm size and aneurysmal rupture was observed in 2 patients with astrocytic or oligodendroglial tumors. We would recommend perioperative treatment of flow-related UIAs in patients with astrocytic or oligodendroglial tumors and noninvasive evaluations such as magnetic resonance angiography if coexisting UIAs remain untreated.

Wall enhancement ratio determined by vessel wall MRI associated with symptomatic intracranial aneurysms

PURPOSE

To study the association of the enhancement ratio (ER) of aneurysmal wall enhancement (AWE) with symptomatic intracranial aneurysms (IAs), we hypothesized that the ER of AWE would be stronger in symptomatic IAs than in asymptomatic IAs, as assessed by high-resolution magnetic resonance imaging (HRMRI).

MATERIALS AND METHODS

Between February 2016 and February 2018, 80 consecutive patients with 89 unruptured IAs were reviewed. Patients and IAs were divided into symptomatic and asymptomatic groups. In addition to the clinical characteristics, the IA features (e.g., size, shape) were evaluated via computed tomography angiography, while the ER and enhanced patterns were evaluated by HRMRI. Multiple logistic regression analysis was performed to determine the independent risk factors for symptomatic IAs. Receiver operating characteristic curve analysis was used for the final model to obtain the optimal thresholds.

RESULTS

Multiple logistic regression analysis indicated that only the ER was associated with symptomatic IAs. The threshold value of the ER was 60.5%.

CONCLUSIONS

A higher ER was more frequently identified in symptomatic IAs. More attention should be paid to this factor in the management of IAs.

Risk factor analysis of recanalization and retreatment for patients with endovascular treatment of internal carotid artery bifurcation aneurysms

PURPOSE

Only a few reports of internal carotid artery (ICA) bifurcation aneurysms using the endovascular technique have been published in the current literature. The purpose of this study was to assess how multiple risk factors including angioarchitectural features of ICA bifurcation characteristics may have influenced aneurysmal rupture, recanalization, and retreatment.

METHODS

Fifty-one patients with 52 ICA bifurcation aneurysms treated with endovascular coiling between July 2003 and July 2015 were retrospectively analyzed. The patients' clinical records, endovascular reports, and clinical and angiographic outcomes were reviewed. We also evaluated risk factors for recanalization and retreatment, including the angioarchitectural anatomy.

RESULTS

The clinical outcomes were observed to be satisfactory in 49 patients (96.0%) and unfavorable in 2 patients (4.0%). The risk factor for aneurysmal rupture was young age (P = 0.024). Symptomatic complications due to thromboembolism occurred in 1.9% of cases; no patients suffered a fatal complication. Eleven of 52 ICA bifurcation aneurysms (21.2%) were recanalized within an average of 54.3 ± 33.5 months of follow-up. Among the aneurysms, 4 (7.7%) underwent recoiling. Multivariate analysis showed that ruptured aneurysms (P = 0.006) and a lower packing density (P = 0.048) were risk factors for recanalization. A lower packing density was the only risk factor for retreatment (P = 0.019).

CONCLUSION

Endovascular treatment of ICA bifurcation aneurysms is considered safe and acceptable. This study showed that the ICA bifurcation aneurysms ruptured more frequently at a younger age. A higher packing density has been shown to reduce major recanalization and retreatment.

Intracranial Aneurysm Is Associated with High Intracranial Artery Tortuosity

BACKGROUND

Although intracranial aneurysms (IAs) are focal bulges of arterial walls, an uncharacterized predisposing factor that affects cerebral arteries may increase tortuosity of intracranial arteries in patients with IAs.

METHODS

Subjects who underwent routine health examinations and magnetic resonance angiography at a university hospital health promotion center were enrolled. Age- and sex-matched control subjects were selected from among individuals who did not have IAs. Tortuosity of right and left middle cerebral arteries and basilar artery (BA) was measured. Distant factor [(arc/chord ratio × 100) - 100] was used to estimate tortuosity. Vascular risk factors and intracranial arterial tortuosities were compared between subjects with IAs and control subjects. Independent factors associated with intracranial artery tortuosity were also investigated.

RESULTS

Of 18,954 (1.9%) subjects, 367 exhibited IAs. The prevalence of hypertension (P = 0.01) and current smoking (P = 0.01) were higher in subjects with IAs than in control subjects. The BA tortuosity was greater in subjects with IAs compared with control subjects (9.0 ± 8.1 vs. 5.5 ± 7.2; P < 0.001). In addition to hypertension, smoking, and absence of coronary artery disease, BA tortuosity (P < 0.001) was independently associated with presence of IAs. The presence of IA (P < 0.001) and absence of coronary artery disease (P = 0.002) were independently associated with high BA tortuosity.

CONCLUSIONS

Patients with IAs exhibit a more tortuous BA. A predisposing factor weakening the cerebrovasculature in patients with IAs may exist and may manifest as high tortuosity of intracranial arteries.

An Integrative Survival Analysis with Identification of Prognostic Factors in the Patients with Coexisting Glioma and Intracranial Aneurysm

OBJECTIVE

This study aimed to perform an integrative clinical and survival analysis for patients with coexisting glioma and intracranial aneurysm and to assess the influence of prognostic factors on overall survival (OS).

METHODS

A systematic literature search on PubMed and Web of Science was performed for literature in English published from 1951 to August 2017. Detailed information including clinical characteristics, treatments, critical events, and time to events for survival analysis was extracted from the included articles. Clinical characteristics of included patients were reviewed, and survival analysis was performed to identify prognostic factors of OS.

RESULTS

A total of 56 cases from 38 articles published in English-language journals were included in this study, and relative details were selected for integrative analysis. Univariate analysis demonstrated that age (<47/≥47 years), ruptured aneurysm (yes/no), glioma type (glioblastoma multiforme [GBM]/no GBM), World Health Organization (WHO) grade (low/high), and radiotherapy (yes/no) had a statistically significant correlation with OS (log-rank P = 0.004, P = 0.037, P = 0.004, P < 0.001, and P < 0.001, respectively). Further, multivariate analysis revealed that WHO grade (hazard ratio [HR], 22.383; 95% confidence interval [CI], 1.795-279.151; P = 0.016) and receiving radiotherapy (HR, 0.054; 95% CI, 0.009-0.333; P = 0.002) were the independent prognostic factors for OS.

CONCLUSIONS

This integrative survival analysis revealed that WHO grade and receiving radiotherapy were independent prognostic factors for OS, and patients with low-grade glioma and receiving radiotherapy had longer survival than counter groups. Nevertheless, similar clinical studies which should be larger samples, multicenter, and collaborative are needed further.