Aneurysm Rupture Status Research Articles

Morphological and Hemodynamic Characteristics Associated With the Rupture of Multiple Intracranial Aneurysms.

Background and PurposeThe objective of this study was to identify the morphological and hemodynamic factors associated with the rupture of multiple intracranial aneurysms regardless of patient-related factors and establish a statistical model for aneurysm rupture risk assessment.MethodsThe digital subtraction angiography (DSA) data of 104 mirror intracranial aneurysms in 52 consecutive patients were retrospectively analyzed in this study. 21 morphological parameters and hemodynamic parameters were calculated by 3-dimensional reconstruction and computational fluid dynamics (CFD) simulation. Significant differences (p < 0.05) between the two groups were subsequently tested with the multivariate logistic regression to identify the independent risk factors. A prediction model was established based on the independent risk factors. The receiver operating characteristics (ROCs) were generated to estimate the prediction performance. A cohort of patients with multiple intracranial aneurysms admitted in our institute from January 2021 to October 2021 was introduced to verify the value of the model.ResultsSignificant differences between the ruptured and unruptured aneurysms were found in 15 out of 19 parameters. Bleb formation, neck width, and size ratio were independent factors in the multivariate logistic regression. A prediction model based on the three independent risk factors was established: Odds = −1.495 – 0.707 × (Neckwidth) + 3.061 × (Blebformation) + 2.1 × (SR) (bleb formation: Yes = 1, No = 0). The area under the curve (AUC) value of the model was 0.901. In the validation cohort, the prediction model showed satisfying performance in assessing multiple aneurysm rupture risk with a sensitivity of 100% and specificity of 88.46%.ConclusionBleb formation, neck width, and size ratio were independently associated with aneurysm rupture status. The prediction model may help in identifying the aneurysm with high rupture risk.

The role of miR-26a, miR-29a and miR-448-3p in the development of cerebral aneurysm.

Cerebral aneurysms cause the weakening and abnormal expansion of the arterial wall. MicroRNAs (miRNAs) are small noncoding RNAs of approximately 22 nucleotides in length that regulate gene expression. This study aimed to elucidate the role of miRNAs in the development of cerebral aneurysms. This study compared the expression levels of miR-26a, miR-29a and miR-448-3p in 50 samples each of cerebral aneurysm tissues and normal superficial temporal artery tissues. The miRNA expression levels were also compared in terms of aneurysm location and rupture status, i.e., presence or absence of rupture. Expression levels of miR-26a, miR-29a and miR-448-3p were increased in aneurysm tissues compared with normal vascular tissues. No significant difference was found in the miRNA expression levels with respect to aneurysm location or rupture status. This study showed that miR-26a, miR-29a and miR-448-3p overexpression could play an important role in intracranial aneurysm development independent of aneurysm location and rupture status. miR-26a, miR-29a and miR-448-3p could act as potential therapeutic targets in patients with intracranial aneurysms; however, further studies are needed on this issue.

Microsurgical management of complex middle cerebral artery aneurysms

Introduction Management of complex aneurysms of the middle cerebral artery (MCA) is very challenging and require individualized treatment strategies. The aim of our review was to analyze experience with the treatment of complex MCA aneurysms using revascularization and artery sacrifice techniques. Methods We have reviewed 9 original articles on patients' treatment with complex MCA aneurysms. Depending on localization of complex aneurysm of MCA various methods of parent artery sacrifice, revascularization strategies, surgical results, outcomes and complications were reviewed. Results We have analyzed treatment of 244 patients with 246 complex MCA aneurysms in 9 different groups. From 67 to 100% of cases the aneurysms were occluded successfully. Bypass patency being a result of the performed revascularization methods was from 83.3 to 100%. The main complications included ischemic disorders related to occlusion of the bypass graft or perforators injury. Morbidity in some reviews varied from 2.4 to 6.9%. The majority of patients in late follow-up showed good outcomes 0-2 on modified Rankin scale and 4-5 on Glasgow Outcome Scale. Illustrative clinical cases of the patients with complex MCA aneurysms treated at the Federal Neurosurgical Center were presented. Conclusion Complex aneurysms of the MCA are very challenging lesions. The surgical strategy for treating complex MCA aneurysm should take into account vascular anatomy, complex aneurysm morphology, its localization and rupture status of each case

Performance of rupture-related morphological parameters in posterior communicating artery aneurysms with fetal-type variant.

The aim of the study was to investigate the impact of fetal-type posterior cerebral artery (fPCA) variant on morphological parameters of posterior communicating artery (PComA) aneurysms for rupture risk assessment. A total of 98 PComA aneurysms (62 ruptured and 36 unruptured) in 98 consecutive patients were reviewed. Morphological parameters were calculated including aneurysm size, aspect ratio (AR), size ratio (SR), dome-to-neck ratio, bottleneck factor and inflow angle. Performances of morphological parameters to discriminate rupture status were compared between aneurysms with or without fPCA. Fetal-type posterior cerebral artery variant was determined in 39 (39.8%, 25 ruptured and 14 unruptured) lesions. The ruptured group revealed a significantly larger size (p = 0.004), AR (p = 0.003), SR (p = 0.001), and inflow angle (p < 0.001). For the aneurysms without fPCA, all morphological parameters were significantly different between ruptured and unruptured aneurysms (p < 0.05); for the aneurysms with fPCA, only inflow angle (p = 0.001) was significantly related with the rupture status. Multivariate analysis showed that SR (p = 0.035 and p = 0.011) and inflow angle (p = 0.001 and p = 0.028) were independent rupture risk factors for the total cohort and the aneurysms without fPCA; while only inflow angle (p = 0.004) revealed to be independently related with rupture status of aneurysms without fPCA. The performances of morphological parameters to discriminate rupture status were different between PComA aneurysms with and without fPCA variants. Inflow angle might be a reliable predictor for rupture risk of PComA aneurysms.

A rare case of ruptured intracranial aneurysm arising from the retro-mastoid branch of the occipital artery

Background: Aneurysms of the occipital artery (OA) are rare, with few cases published in the literature. The pathophysiology is unknown, and the presentation is variable. We present a case of a ruptured intracranial aneurysm arising from a branch of the OA.Case Description: A 36-year-old male with a history of ankylosing spondylitis presented with altered mental status after an assaulted. On examination, he was intubated, with a Glasgow coma scale of 9, and imaging of the head and neck revealed a subdural hematoma of the posterior fossa and the cervical spine. The patient underwent suboccipital craniectomy and C1-5 laminectomy with the evacuation of the subdural hematoma. Postoperative cerebral angiography showed an intracranial aneurysm arising from the retromastoid branch of the OA on the left side. Furthermore, the parent vessel of the aneurysm supplied the left lower half of the cerebellar hemisphere. The aneurysm and the parent vessel were embolized using platinum coils. The patient tolerated the procedure well, and magnetic resonance imaging of the brain showed a minor left-sided cerebellar infarct, which was asymptomatic. The patient was discharged home with a modified Rankin scale of 2. There were no outpatient follow-up data available because the patient lost to follow-up.Conclusion: Intracranial OA aneurysms are extremely rare with no clear consensus concerning the management of these aneurysms. They can be treated using endovascular and or open surgical techniques depending on the aneurysm characteristics, patient condition, rupture status, and others.

Development and validation of an institutional nomogram for aiding aneurysm rupture risk stratification

Rupture risk stratification is critical for incidentally detected intracranial aneurysms. Here we developed and validated an institutional nomogram to solve this issue. We reviewed the imaging and clinical databases for aneurysms from January 2015 to September 2018. Aneurysms were reconstructed and morphological features were extracted by the Pyradiomics in python. Multiple logistic regression was performed to develop the nomogram. The consistency of the nomogram predicted rupture risks and PHASES scores was assessed. The performance of the nomogram was evaluated by the discrimination, calibration, and decision curve analysis (DCA). 719 aneurysms were enrolled in this study. For each aneurysm, twelve morphological and nine clinical features were obtained. After logistic regression, seven features were enrolled in the nomogram, which were SurfaceVolumeRatio, Flatness, Age, Hyperlipemia, Smoker, Multiple aneurysms, and Location of the aneurysm. The nomogram had a positive and close correlation with PHASES score in predicting aneurysm rupture risks. AUCs of the nomogram in discriminating aneurysm rupture status was 0.837 in a separate testing set. The calibration curves fitted well and DCA demonstrated positive net benefits of the nomogram in guiding clinical decisions. In conclusion, Pyradiomics derived morphological features based institutional nomogram was useful for aneurysm rupture risk stratification.

Cerebral aneurysm rupture status classification using statistical and machine learning methods.

Morphological characterization and fluid dynamics simulations were carried out to classify the rupture status of 71 (36 unruptured, 35 ruptured) patient specific cerebral aneurysms using a machine learning approach together with statistical techniques. Eleven morphological and six hemodynamic parameters were evaluated individually and collectively for significance as rupture status predictors. The performance of each parameter was inspected using hypothesis testing, accuracy, confusion matrix, and the area under the receiver operating characteristic curve. Overall, the size ratio exhibited the best performance, followed by the diastolic wall shear stress, and systolic wall shear stress. The prediction capability of all 17 parameters together was evaluated using eight different machine learning algorithms. The logistic regression achieved the highest accuracy (0.75), whereas the random forest had the highest area under curve value among all the classifiers (0.82), surpassing the performance exhibited by the size ratio. Hence, we propose the random forest model as a tool that can help improve the rupture status prediction of cerebral aneurysms.

Machine Learning-Based Prediction of Small Intracranial Aneurysm Rupture Status Using CTA-Derived Hemodynamics: A Multicenter Study.

Small intracranial aneurysms are being increasingly detected while the rupture risk is not well-understood. We aimed to develop rupture-risk models of small aneurysms by combining clinical, morphologic, and hemodynamic information based on machine learning techniques and to test the models in external validation datasets. From January 2010 to December 2016, five hundred four consecutive patients with only small aneurysms (<5 mm) detected by CTA and invasive cerebral angiography (or surgery) were retrospectively enrolled and randomly split into training (81%) and internal validation (19%) sets to derive and validate the proposed machine learning models (support vector machine, random forest, logistic regression, and multilayer perceptron). Hemodynamic parameters were obtained using computational fluid dynamics simulation. External validation was performed in other hospitals to test the models. The support vector machine performed the best with areas under the curve of 0.88 (95% CI, 0.85-0.92) and 0.91 (95% CI, 0.74-0.98) in the training and internal validation datasets, respectively. Feature ranks suggested hemodynamic parameters, including stable flow pattern, concentrated inflow streams, and a small (<50%) flow-impingement zone, and the oscillatory shear index coefficient of variation, were the best predictors of aneurysm rupture. The support vector machine showed an area under the curve of 0.82 (95% CI, 0.69-0.94) in the external validation dataset, and no significant difference was found for the areas under the curve between internal and external validation datasets (P = .21). This study revealed that machine learning had a good performance in predicting the rupture status of small aneurysms in both internal and external datasets. Aneurysm hemodynamic parameters were regarded as the most important predictors.

Performance of Radiomics derived morphological features for prediction of aneurysm rupture status

BackgroundMorphological differences between ruptured and unruptured cerebral aneurysms represent a focus of neuroimaging researchfor understanding the mechanisms of aneurysmal rupture. We evaluated the performance of Radiomics derived morphological features, recently...

Quantitative analysis of flow vortices: differentiation of unruptured and ruptured medium-sized middle cerebral artery aneurysms.

Surgical intervention for unruptured intracranial aneurysms (IAs) carries inherent health risks. The analysis of "patient-specific" IA geometric and computational fluid dynamics (CFD) simulated wall shear stress (WSS) data has been investigated to differentiate IAs at high and low risk of rupture to help clinical decision making. Yet, outcomes vary among studies, suggesting that novel analysis could improve rupture characterization. The authors describe a CFD analytic method to assess spatiotemporal characteristics of swirling flow vortices within IAs to improve characterization. CFD simulations were performed for 47 subjects harboring one medium-sized (4-10mm) middle cerebral artery (MCA) aneurysm with available 3D digital subtraction angiography data. Alongside conventional indices, quantified IA flow vortex spatiotemporal characteristics were applied during statistical characterization. Statistical supervised machine learning using a support vector machine (SVM) method was run with cross-validation (100 iterations) to assess flow vortex-based metrics' strength toward rupture characterization. Relying solely on vortex indices for statistical characterization underperformed compared with established geometric characteristics (total accuracy of 0.77 vs 0.80) yet showed improvements over wall shear stress models (0.74). However, the application of vortex spatiotemporal characteristics into the combined geometric and wall shear stress parameters augmented model strength for assessing the rupture status of middle cerebral artery aneurysms (0.85). This preliminary study suggests that the spatiotemporal characteristics of flow vortices within MCA aneurysms are of value to improve the differentiation of ruptured aneurysms from unruptured ones.

Risk Factors of Angiographic Recurrence After Endovascular Coil Embolization of Intracranial Saccular Aneurysms: A Retrospective Study Using a Multicenter Database

Background: Endovascular therapy of intracranial aneurysms has a high recurrence rate. This study aimed to evaluate the risk factors of recurrence after endovascular coil embolization of intracranial aneurysms.Methods: From January 2014 to May 2015, 504 patients with 558 intracranial aneurysms who were treated by endovascular therapy were recruited from four high-volume centers. We used multivariate Cox proportional hazard regression to evaluate the risk factors associated with the angiographic recurrence of intracranial saccular aneurysms after endovascular coil embolization.Results: Angiographic follow-up was available for 504 patients (558 aneurysms), with a mean duration of 11.42 months. Of the 558 aneurysms, 57 (10.2%) aneurysms showed recurrence. Aneurysm size (p = 0.028), therapy (non-stent assisted coiling or stent-assisted coiling) (p = 0.008), the Raymond scale (p = 0.040), aneurysm rupture status (p < 0.001), and packing density (p < 0.001) showed significant associations with angiographic follow-up outcome. A low packing density was independently associated with aneurysmal recurrence after multivariate Cox proportional hazard regression analysis (p < 0.001).Conclusion: Endovascular treatment is effective for these lesions. Multiple factors could attribute to the aneurysmal recurrence after endovascular coil embolization. The low packing density is the independent risk factor for aneurysmal recurrence. These findings should be verified by larger multicenter and multi-population studies.

Treatment of Ruptured and Unruptured Intracranial Aneurysms with WEB17 Versus WEB21 Systems : Comparison of Indications and Early Angiographic Outcomes.

The concept of intrasaccular flow diversion using the Woven EndoBridge (WEB) device changed the traditional endovascular concept for wide-necked bifurcation aneurysms. The latest technical advancement resulted in the WEB17 system, asofter device composed of fewer wires which enables treatment of smaller more distally located aneurysms by using smaller microcatheters as compared to the WEB21 system. This retrospective observational study aimed to evaluate and compare the angiographic and clinical results achieved with WEB21 and WEB17 in aneurysm morphologies eligible for both systems (maximum width 3-6 mm). Between August 2014 and August 2019 atotal of 63and 130 aneurysms with amaximum width of 3-6 mm were treated with either WEB21 and WEB 17, respectively, at 2neurovascular centers. Cases were analyzed based on acomparison regarding aneurysm size, location and rupture status. The technical success, the periprocedural complication rate and the rate of additional devices used showed no relevant differences between the two groups. Aneurysms treated with the WEB17 system were smaller and more frequently distally located. The overall complete occlusion rate at 3months was higher in the WEB17 group (65.5% versus 55.1%). The superiority of complete aneurysm occlusion achieved with WEB17 was statistically significant in the subgroup of unruptured middle cerebral artery aneurysms. The use of WEB17 expands the treatment indications for intrasaccular flow-diversion towards smaller and more distally located aneurysms with asafety profile comparable with that of the WEB21.

Discrimination of intracranial aneurysm rupture status: patient-specific inflow boundary may not be a must-have condition in hemodynamic simulations.

Computational fluid dynamics (CFD) are important in evaluating the hemodynamics of intracranial aneurysm rupture, and the setting of inflow boundary conditions is critical. We evaluated intracranial aneurysm hemodynamics based on generalized versus patient-specific inflow boundary conditions to examine the effect of different hemodynamic results on the discrimination of intracranial aneurysm rupture status. We enrolled 148 patients with 156 intracranial aneurysms. For each included aneurysm, we performed CFD simulation once based on patient-specific and once based on generalized inflow boundary conditions. First, we compared the hemodynamics of intracranial aneurysms based on different inflow boundary conditions. Then, we divided the included aneurysms into a ruptured and unruptured group and compared the hemodynamics between the two groups under patient-specific and generalized inflow boundary conditions. For the hemodynamic parameters using specific inflow boundary conditions, more complex flow (p = 0.002), larger minimum WSS (p = 0.024), lower maximum low WSS area (LSA) (p = 0.038), and oscillatory shear index (p = 0.002) were found. Furthermore, we compared the hemodynamics between ruptured and unruptured groups based on different inflow boundary conditions. We found that the significant hemodynamic parameters associated with rupture status were the same, including the proportion of aneurysms with flow complex and unstable flow and the minimum and maximum of LSA (p = 0.011, p = 0.003, p = 0.001 and p = 0.004, respectively). Patient-specific and generalized inflow boundary conditions of aneurysmal hemodynamics resulted in significant differences. However, the significant parameters associated with rupture status were the same in both conditions, indicating that patient-specific inflow boundary conditions may not be necessary for predicting rupture risk.

Shape irregularity of the intracranial aneurysm lumen exhibits diagnostic value.

Morphological irregularity is linked to intracranial aneurysm wall instability and manifests in the lumen shape. Yet there is currently no consent on how to assess shape irregularity. The aims of this work are to quantify irregularity as perceived by clinicians, to break down irregularity into morphological attributes, and to relate these to clinically relevant factors such as rupture status, aneurysm location, and patient age or sex. Thirteen clinicians and 26 laypersons assessed 134 aneurysm lumen segmentations in terms of overall perceived irregularity and five different morphological attributes (presence/absence of a rough surface, blebs, lobules, asymmetry, complex geometry of the parent vasculature). We examined rater agreement and compared the ratings with clinical factors by means of regression analysis or binary classification. Using rank-based aggregation, the irregularity ratings of clinicians and laypersons did not differ statistically. Perceived irregularity showed good agreement with curvature (coefficient of determination R2 = 0.68 ± 0.08) and was modeled very accurately using the five morphological rating attributes plus shape elongation (R2 = 0.95 ± 0.02). In agreement with previous studies, irregularity was associated with aneurysm rupture status (AUC = 0.81 ± 0.08); adding aneurysm location as an explanatory variable increased the AUC to 0.87 ± 0.09. Besides irregularity, perceived asymmetry, presence of blebs or lobules, aneurysm size, non-sphericity, and curvature were linked to rupture. No association was found between morphology and any of patient sex, age, and history of smoking or hypertension. Aneurysm size was linked to morphology. Irregular lumen shape carries significant information on the aneurysm's disease status. Irregularity constitutes a continuous parameter that shows a strong association with the rupture status. To improve the objectivity of morphological assessment, we suggest examining shape through six different morphological attributes, which can characterize irregularity accurately.

Development and validation of machine learning prediction model based on computed tomography angiography-derived hemodynamics for rupture status of intracranial aneurysms: a Chinese multicenter study.

To build models based on conventional logistic regression (LR) and machine learning (ML) algorithms combining clinical, morphological, and hemodynamic information to predict individual rupture status of unruptured intracranial aneurysms (UIAs), afterwards tested in internal and external validation datasets. Patients with intracranial aneurysms diagnosed by computed tomography angiography and confirmed by invasive cerebral angiograph or clipping surgery were included. The prediction models were developed based on clinical, aneurysm morphological, and hemodynamic parameters by conventional LR and ML methods. The training, internal validation, and external validation cohorts were composed of 807 patients, 200 patients, and 108 patients, respectively. The area under curves (AUCs) of conventional LR models 1 (clinical), 2 (clinical and aneurysm morphological), and 3 (clinical, aneurysm morphological and hemodynamic characteristics) were 0.608, 0.765, and 0.886, respectively (all p < 0.05). The AUCs of ML models using random forest (RF), multilayer perceptron (MLP), and support vector machine (SVM) were 0.871, 0.851, and 0.863, respectively. There were no difference among AUCs of conventional LR, RF, and SVM (all p > 0.05/6), while the AUC of MLP was lower than that of conventional LR (p = 0.0055). Hemodynamic parameters play an important role in the prediction performance of the models. ML methods cannot outperform conventional LR in prediction models for rupture status of UIAs integrating clinical, aneurysm morphological, and hemodynamic parameters. • The addition of hemodynamic parameters can improve prediction performance for rupture status of unruptured intracranial aneurysms. • Machine learning algorithms cannot outperform conventional logistic regression in prediction models for rupture status integrating clinical, aneurysm morphological, and hemodynamic parameters. • Models integrating clinical, aneurysm morphological, and hemodynamic parameters may help choose the optimal management.

Factors affecting recurrence and management of recurrent cerebral aneurysms after initial coiling.

To investigate factors affecting recurrence and effects and safety of endovascular retreatment for aneurysms recurrent after embolization. Among 815 aneurysms treated with embolization, recurrence was in 114 aneurysms (14.0%). Forty-three recurrent aneurysms were managed with re-embolization. Procedural complications, angiographic, and clinical results of retreatment were analyzed. Patients with recurrent aneurysms were significantly (P < 0.01) younger than without recurrence (51.09 ± 10.46 vs. 53.88 ± 9.61 years). Recurrent aneurysms (n = 114) were significantly (P = 0.00) greater (11.12 ± 8.35 vs. 5.81 ± 3.44 mm) with a significantly (P = 0.00) greater neck (4.34 ± 2.26 vs. 2.90 ± 1.44 mm) than without recurrence. The rupture status of aneurysms significantly (P = 0.00) affected recurrence at follow-up. Significantly (P = 0.00) more aneurysms without recurrence were treated with advanced embolization techniques (81.0% vs. 62.3%) and got complete occlusion at the first embolization than those with recurrence (93.7% vs. 36.8%). In treating 43 recurrent aneurysms, stent-assisted recoiling was used in 48.8% in the first retreatment and 50% in the second and third retreatment procedures. Angiographic follow-up in 38 (88.4%) cases showed complete or near complete occlusion in 30 aneurysms, with the rest eight aneurysms experiencing a second recurrence (21.1%). Of the eight aneurysms with the second recurrence, five underwent the second endovascular retreatment, with complete aneurysm occlusion achieved in three cases (60%), near-complete occlusion in one (20%), and incomplete occlusion in one case at immediate angiography and six-month follow-up. Procedure-related complications occurred in three patients. Endovascular retreatment of recurrent previously coiled aneurysms is safe and effective even though advanced embolization techniques are frequently involved especially for large and giant aneurysms.

Machine Learning Classification of Cerebral Aneurysm Rupture Status with Morphologic Variables and Hemodynamic Parameters.

To construct a classification model of rupture status and to clarify the importance of morphologic variables and hemodynamic parameters on rupture status by applying a machine learning (ML) algorithm to morphologic and hemodynamic data of cerebral aneurysms. Between 2011 and 2019, 226 (112 ruptured and 114 unruptured) cerebral aneurysms in 188 consecutive patients were retrospectively analyzed with computational fluid dynamics (CFD). A random forest ML algorithm was applied to the results to create three classification models consisting of only morphologic variables (model 1), only hemodynamic parameters (model 2), and both morphologic variables and hemodynamic parameters (model 3). The accuracy of rupture status classification and the importance of each variable or parameter in the models were computed. The accuracy was 77.0% in model 1, 71.2% in model 2, and 78.3% in model 3. The three most important features were projection ratio, size ratio, and aspect ratio in model 1; low shear area ratio, oscillatory shear index, and oscillatory velocity index in model 2; and projection ratio, irregular shape, and size ratio in model 3. Classification models of rupture status of cerebral aneurysms were constructed by applying an ML algorithm to morphologic variables and hemodynamic parameters. The model worked with relatively high accuracy, in which projection ratio, irregular shape, and size ratio were important for the discrimination of ruptured aneurysms.Supplemental material is available for this article.© RSNA, 2020.

Impaired cerebrovascular reactivity may predict delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

IntroductionDelayed cerebral ischemia (DCI) is a major cause of disability and death after aneurysmal subarachnoid hemorrhage. The literature suggests that impaired cerebrovascular reactivity (CVR) may be a predictor for DCI; still no CVR based prediction model has been developed. Increased knowledge about possible predictors of DCI can improve patient management in high-risk patients and allow for shorter hospital stay in low-risk patients. MethodCVR was examined in 42 patients with aneurysmal subarachnoid hemorrhage and 37 patients treated for unruptured intracranial aneurysm, using acetazolamide test with transcranial Doppler monitoring of blood flow velocities. Patients were followed for development of DCI, separated into clinical deterioration and radiographic infarction. ResultsFor all patients, regardless of aneurysm rupture status, CVR was on average 5.5 percentage points lower on the ipsilateral side of aneurysm treatment. Patients with clinical deterioration due to DCI had lower CVR than patients without DCI, and the difference was larger on the contralateral side (33.9% vs. 49.2%). Two prediction models were constructed for clinical deterioration due to DCI. The area under the receiver operating characteristic curve was 0.82 in the model using established predictors, and 0.86 in the model that also included CVR. ConclusionOur findings support the hypothesis that impaired CVR may be an independent predictor of clinical deterioration due to DCI, and may assist in identifying patients at risk after aneurysmal subarachnoid hemorrhage. Ipsilateral CVR reduction occurs in all patients after aneurysm treatment, regardless of DCI development, thus highlighting the need to evaluate ipsi- and contralateral CVR separately.

High wall shear stress beyond a certain range in the parent artery could predict the risk of anterior communicating artery aneurysm rupture at follow-up.

Among clinical and morphological criteria, hemodynamics is the main predictor of aneurysm growth and rupture. This study aimed to identify which hemodynamic parameter in the parent artery could independently predict the rupture of anterior communicating artery (ACoA) aneurysms by using multivariate logistic regression and two-piecewise linear regression models. An additional objective was to look for a more simplified and convenient alternative to the widely used computational fluid dynamics (CFD) techniques to detect wall shear stress (WSS) as a screening tool for predicting the risk of aneurysm rupture during the follow-up of patients who did not undergo embolization or surgery. One hundred sixty-two patients harboring ACoA aneurysms (130 ruptured and 32 unruptured) confirmed by 3D digital subtraction angiography at three centers were selected for this study. Morphological and hemodynamic parameters were evaluated for significance with respect to aneurysm rupture. Local hemodynamic parameters were obtained by MR angiography and transcranial color-coded duplex sonography to calculate WSS magnitude. Multivariate logistic regression and a two-piecewise linear regression analysis were performed to identify which hemodynamic parameter independently characterizes the rupture status of ACoA aneurysms. Univariate analysis showed that WSS (p < 0.001), circumferential wall tension (p = 0.005), age (p < 0.001), the angle between the A1 and A2 segments of the anterior cerebral artery (p < 0.001), size ratio (p = 0.023), aneurysm angle (p < 0.001), irregular shape (p = 0.005), and hypertension (grade II) (p = 0.006) were significant parameters. Multivariate analyses showed significant association between WSS in the parent artery and ACoA aneurysm rupture (p = 0.0001). WSS magnitude, evaluated by a two-piecewise linear regression model, was significantly correlated with the rupture of the ACoA aneurysm when the magnitude was higher than 12.3 dyne/cm2 (HR 7.2, 95% CI 1.5-33.6, p = 0.013). WSS in the parent artery may be one of the reliable hemodynamic parameters characterizing the rupture status of ACoA aneurysms when the WSS magnitude is higher than 12.3 dyne/cm2. Analysis showed that with each additional unit of WSS (even with a 1-unit increase of WSS), there was a 6.2-fold increase in the risk of rupture for ACoA aneurysms.

Residuals, recurrences and re-treatment after endovascular repair of intracranial aneurysms: A retrospective methodological comparison.

Incomplete aneurysm occlusions and re-treatment rates of 52 and 10-30%, respectively, have been reported following endovascular treatment of intracranial aneurysms, raising clinical concerns regarding procedural efficacy. We compare residual, recurrence and re-treatment rates subject to different endovascular techniques in both ruptured and unruptured intracranial aneurysms at a comprehensive state-wide tertiary neurovascular centre in Australia. Medical records, procedural and follow-up imaging studies of all patients who underwent endovascular treatment for intracranial aneurysms between July 2010 and July 2017 were reviewed retrospectively. Residuals, recurrences and re-treatment rates were assessed regarding initial aneurysm rupture status and applied endovascular technique: primary coiling, balloon- and stent-assisted coiling and flow diversion. Among 233 aneurysms, residual, recurrence and re-treatment rates were 27, 11.2 and 9.4%, respectively. Compared with unruptured aneurysms, similar residual and recurrence (p > .05), but higher re-treatment rates (4.5% vs. 19%; p < .001) were found for ruptured aneurysms. Residual, recurrence and re-treatment rates were: 13.3, 16 and 12% for primary coiling; 12, 12 and 10.7% for balloon-assisted coiling; 14.9, 7.5 and 4.5% for stent-assisted coiling; 91.9, 0 and 5.4% for flow diversion. Stent-assistance and flow-diversion were associated with lower recurrence and re-treatment rates, when compared with primary- and balloon-assisted coiling (p < .05). Residuals and recurrences after endovascular treatment of intracranial aneurysms are less common than previously reported. Stent assistance and flow diversion seem associated with reduced recurrence- and re-treatment rates, when compared with primary- and balloon-assisted coiling. Restrained use of stents in ruptured aneurysms may be a contributing factor for higher recurrence/retreatment rates compared to unruptured aneurysms.