Sarcopenia as a Predictor of the Functional Outcome in Patients with Intracranial Aneurysms

INTRODUCTION

Radiological indicators in head computed tomography (CT) scan have emerged as tools to evaluate sarcopenia using the sectional area and thickness of the temporal muscle. They can be obtained by standardized measurements in preoperative image assessment of patients with brain aneurysms. We aimed to evaluate the association between functional outcomes after interventions for intracranial aneurysms (IAs) and temporal muscle thickness (TMT) and area (TMA), as surrogates of sarcopenia.

METHODS

This is a prospective observational cohort study in patients who underwent microsurgery or embolization for ruptured or unruptured IA between January 2018 and December 2019, with a 6-month follow-up. Preoperative CT scans were analyzed to measure TMT and TMA. The functional outcome was assessed by the modified Rankin Scale (mRS). The main outcome was the relationship between sarcopenia and the postoperative functional outcome.

RESULTS

A total of 361 patients were included, of whom 199 (55.1%) had ruptured and 162 (44.9%) had unruptured lesions. Larger TMA significantly predicted better functional outcomes at discharge. TMT was associated with functional outcomes at both discharge and 6 months, adjusted for rupture and hypertension. Maximizing the sum sensitivity-specificity, an optimal TMT cutoff of 6.25 mm can predict unfavorable outcomes. Maximizing the positive predictive value × negative predictive value of a product, the cutpoint was 3.55 mm.

CONCLUSIONS

Sarcopenia, represented by TMT and TMA, is associated with poorer functional results at discharge and 6-month follow-up in IA surgery. TMT below 6.25 mm was associated with unfavorable functional outcomes. These easily obtainable measurements may improve the decision-making process for patients with IAs.

A comparison of antiplatelet therapy during the peri- and post-operative periods following flow-diverting stent insertion for unruptured intracranial aneurysms: A systematic review

BACKGROUND

Flow diverters (FDs) are neuroendovascular stents indicated for the management of unruptured intracranial aneurysms. Due to their composition, dual antiplatelet therapy (DAPT) is essential during the peri- and post-operative periods to prevent thromboembolic events. However, there is limited consensus within the scientific community regarding which antiplatelets to use and dosing following neuroendovascular treatment of aneurysms.

METHOD

A systematic search of four electronic databases was conducted during November 2020 that included studies published between January 2010 and November 2020. Eligibility for inclusion included primary research articles, published in the English language and use of flow-diverting intracranial stents. Studies were excluded if they utilised combined therapies (e.g. FD with stent-assisted coiling), animal studies, clinical trial protocols and study population of less than 10 subjects.

RESULTS

Eighteen studies were identified for inclusion with a total of 1312 patients with 1355 unruptured intracranial aneurysms treated with FDs. Of these, 13 studies primarily investigated the use of clopidogrel with aspirin with low rates of haemorrhagic and thromboembolic complications. A forest plot of nine of these studies showed average efficacy of 88% at 95% confidence interval (CI) (SD + 5%) with 63% heterogeneity.

CONCLUSIONS

The large proportion of studies investigating clopidogrel and aspirin antiplatelet therapy presents a challenge in comparing antiplatelet regimens. Although prasugrel and ticagrelor have been identified as suitable alternatives to clopidogrel, these were based on studies with small cohort sizes. Glycoprotein IIb/IIIa inhibitors may be efficacious as rescue therapy for intra-procedural thrombosis. Further research is required to determine which antiplatelet is most suitable.

Hemodynamics of anterior circulation intracranial aneurysms with daughter blebs: investigating the multidirectionality of blood flow fields

Recent advances in diagnostic neuroradiological imaging, allowed the detection of unruptured intracranial aneurysms (IAs). The shape - irregular or multilobular - of the aneurysmal dome, is considered as a possible rupture risk factor, independently of the size, the location and patient medical background. Disturbed blood flow fields in particular is thought to play a key role in IAs progression. However, there is an absence of widely-used hemodynamic indices to quantify the extent of a multi-directional disturbed flow. We simulated blood flow in twelve patient-specific anterior circulation unruptured intracranial aneurysms with daughter blebs utilizing the spectral/hp element framework Nektar++. We simulated three cardiac cycles using a volumetric flow rate waveform while we considered blood as a Newtonian fluid. To investigate the multidirectionality of the blood flow fields, besides the time-averaged wall shear stress (TAWSS), we calculated the oscillatory shear index (OSI), the relative residence time (RRT) and the time-averaged cross flow index (TACFI). Our CFD simulations suggest that in the majority of our vascular models there is a formation of complex intrasaccular flow patterns, resulting to low and highly oscillating WSS, especially in the area of the daughter blebs. The existence of disturbed multi-directional blood flow fields is also evident by the distributions of the RRT and the TACFI. These findings further support the theory that IAs with daughter blebs are linked to a potentially increased rupture risk.

Plasticity of the adult circle of Willis in response to flow diversion stents

Background

We present five patients with remodeling of the adult circle of Willis in response to flow diverter stents (FDSs) at the anterior communicating artery (AComA) and the posterior communicating artery (PComA). The observed changes provide a paradigm of how flow change can institute anatomic changes in the adult circle of Willis vasculature.

Case Description

In the first two cases, after placement of the FDS covering the AComA, there was an increase in size and flow of the contralateral A1-anterior cerebral artery which had previously been hypoplastic. In one of the cases, this led to the filling of the aneurysm and required placement of coils within the lesion which was curative. In case three, the FDS effect led to asymptomatic occlusion of the PComA and associated aneurysm without change of the ipsilateral P1-segement of posterior-cerebral-artery (P1-PCA) caliber. In the fourth case, the FDS covering an aneurysm with a fetal PCA arising from its neck resulted in significant reduction of the aneurysm size, persistent flow and caliber of the fetal PCA, and the hypoplastic ipsilateral P1-PCA. Finally, in the fifth case, after FDS occlusion of the PComA and aneurysm there was increasement in diameter of the ipsilateral P1-PCA that was previously hypoplastic.

Conclusion

The use of FDS can affect vessels covered by the device and other arteries of the circle of Willis adjacent to the FDS. The phenomena illustrated in the hypoplastic branches appear to be a compensatory response to the hemodynamic changes induced by the divertor and to the altered flow in the circle of Willis.

Should we screen for intracranial aneurysms in children with autosomal dominant polycystic kidney disease?

This is an overview of the challenges associated with screening for asymptomatic intracranial aneurysms (ICA) in children with autosomal dominant polycystic kidney disease (ADPKD). ADPKD is the most common inherited kidney disease affecting 1 in 1,000 people. ICAs are an extra-kidney manifestation of ADPKD, and while the exact pathophysiology of how they develop is unknown, we know that they more commonly occur in the adult rather than paediatric population. ICAs can be found in up to 9-11.5% of adults with ADPKD, but ICA rupture remains a rare event in adults with an incidence of 0.04 per 100 patient years. ICA size is an important factor in determining the risk of aneurysm rupture and therefore affects the decision on intervention in asymptomatic adults. For some, unruptured aneurysms cause no clinical significance, but those that rupture can be associated with devastating morbidity and mortality. Therefore, if detected, the treatment for unruptured ICAs is usually endovascular coiling, alongside recognising the importance of preventative interventions such as hypertension management. There are, however, no current guidelines for either adult or paediatric patients with ADPKD supporting regular screening for asymptomatic ICAs, although there is a suggestion for individualised practice, for example, with those with a positive family history. The UK clinical guidelines for ADPKD in children make research recommendations due to a lack of published literature, which in itself indicates that ICA rupture is an extremely rare phenomenon in children.

Genetic association between the lncRNA ANRIL rs10757272 polymorphism and intracranial aneurysm susceptibility in Asians

Current epidemiological studies reporting the role of lncRNA ANRIL rs10757272 polymorphism and intracranial aneurysm risk remain controversial. In the present study, we conducted a meta-analysis to resolve this inconsistency. PubMed and EMBASE databases were retrieved to collect the publications evaluating the association with a time limit of August 20, 2021. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of the association. Subgroup analysis, heterogeneity analyses, and publication bias were assessed in the meta-analysis. Finally, 2853 cases and 13,426 controls were enrolled in this meta-analysis based on inclusion criteria. The pooled results indicated that the rs10757272 polymorphism is significantly associated with the risk of intracranial aneurysms in all genetic models (homozygous model, odds ratio (OR) = 1.48, 95% confidence interval (CI) = 1.28-1.71, Pheterogeneity = 0.11, I2 = 50.9; heterozygous model, OR = 1.26, 95% CI = 1.09-1.46, Pheterogeneity = 0.15, I2 = 42.8; dominant model, OR = 1.37, 95% CI = 1.19-1.57, Pheterogeneity = 0.12, I2 = 48.1; and recessive model, OR = 1.23, 95% CI = 1.13-1.34, Pheterogeneity = 0.24, I2 = 28.8). Subgroup analyses showed consistent results. In conclusion, our findings provided evidence that the rs10757272 polymorphism is associated with susceptibility to intracranial aneurysms in Asians.

A numerical investigation of the mechanics of intracranial aneurysms walls: Assessing the influence of tissue hyperelastic laws and heterogeneous properties on the stress and stretch fields

Numerical simulations have been extensively used in the past two decades for the study of intracranial aneurysms (IAs), a dangerous disease that occurs in the arteries that reach the brain and affect overall 3.2% of a population without comorbidity with up to 60% mortality rate, in case of rupture. The majority of those studies, though, assumed a rigid-wall model to simulate the blood flow. However, to also study the mechanics of IAs walls, it is important to assume a fluid-solid interaction (FSI) modeling. Progress towards more reliable FSI simulations is limited because FSI techniques pose severe numerical difficulties, but also due to scarce data on the mechanical behavior and material constants of IA tissue. Additionally, works that have investigated the impact of different wall modeling choices for patient-specific IAs geometries are a few and often with limited conclusions. Thus our present study investigated the effect of different modeling approaches to simulate the motion of an IA. We used three hyperelastic laws - the Yeoh law, the three-parameter Mooney-Rivlin law, and a Fung-like law with a single parameter - and two different ways of modeling the wall thickness and tissue mechanical properties - one assumed that both were uniform while the other accounted for the heterogeneity of the wall by using a "hemodynamics-driven" approach in which both thickness and material constants varied spatially with the cardiac-cycle-averaged hemodynamics. Pulsatile numerical simulations, with patient-specific vascular geometries harboring IAs, were carried out using the one-way fluid-solid interaction solution strategy implemented in solids4foam, an extension of OpenFOAM®, in which the blood flow is solved and applied as the driving force of the wall motion. We found that different wall morphology models yield smaller absolute differences in the mechanical response than different hyperelastic laws. Furthermore, the stretch levels of IAs walls were more sensitive to the hyperelastic and material constants than the stress. These findings could be used to guide modeling decisions on IA simulations, since the computational behavior of each law was different, for example, with the Yeoh law being the fastest to converge.

METEOROLOGICAL VARIABLES ASSOCIATED WITH SUBARACHNOID HEMORRHAGE: A SINGLE CENTER STUDY

Spontaneous subarachnoid hemorrhage (SAH) can occur unexpectedly and independently of the classic risk factors. Several different factors could affect intracranial aneurysm (IA) rupture, such as morphological and hemodynamic factors. The aim of this study was to establish the potential association of meteorological data such as temperature, atmospheric pressure, and humidity, and the onset of clinical symptoms preceding hospital admission of patients with acute SAH due to IA rupture. This retrospective study included 130 consecutive patients admitted for non-traumatic SAH with a determinable onset of SAH symptoms. The effects of meteorological parameters of atmospheric pressure, ambient temperature, and relative air humidity on the day of acute SAH onset and 24 hours prior to the onset of symptoms were recorded and analyzed in each patient. Spearman rank correlation analysis was used to assess the risks of incident SAH on the basis of daily meteorological data. Seasonal incidence of acute SAH showed the peak incidence in winter and a trough in summer, with monthly incidence peak in January and December. The circadian rhythm analysis showed the peak incidence of SAH in the forenoon, followed by the evening. Acute SAH incidence showed moderate positive association with daily atmospheric pressure (p<0.05), while no association was found with ambient temperature and relative air humidity. Our results suggested no significant association of changes in ambient temperature and relative humidity with the risk of SAH. Increases in atmospheric pressure were weakly associated with a higher SAH risk. Additional studies are needed to establish in detail both meteorological and morphological factors important to predict IA rupture and SAH.

Hemodynamics and bio-mechanics of morphologically distinct saccular intracranial aneurysms at bifurcations: Idealised vs Patient-specific geometries

Understanding the factors that influence the rupture of aneurysms is of primary concern to the clinicians, who are grappled with patient management. It is important to know how the relation between morphological features of the cerebral aneurysm, and the mechanical stresses on the containing arterial walls are influenced by the hemodynamic forces. Present study investigates three different shapes, which have been identified correspondingly in patient-specific scenarios as well. The primary objective is to categorize the bifurcation aneurysms into standard shapes such as, spherical, beehive and pear-shaped, based on patient-specific clinical studies and further compare and contrast the model aneurysms with the patient specific configurations, for their hemodynamic factors as well as the attendant stresses on the wall. MethodsComputational fluid dynamic simulations are performed accounting for the fluid-structure interaction (FSI) effects between the flowing fluid and the containing vessel wall. Blood is assumed to be Newtonian, while the arterial walls are assumed to be linearly elastic. A commercial solver is used for performing detailed calculations. Hemodynamic and bio-mechanical rupture predictions are carried out for the three different shapes. Observations derived from the idealised simulations are compared and contrasted against their patient-specific counterparts. ResultsFrom detailed numerical simulations, it was observed that pear-shaped aneurysms exhibit large re-circulation bubble and flow stagnation zone, with higher residence time for the particles, which may lead to atherosclerotic lesions. Beehive shape allows for maximum flow into the aneurysmal sac with concentrated jet impinging on the dome, leading to high values of maximum WSS (MWSS) resulting in great propensity to form a secondary bleb. However, flow field inside a spherical aneurysm is found to be stable with fewer vortices, and nearly uniform distribution of wall stresses are observed though-out the sac, which perhaps signifies hemodynamically and bio-mechanically stable condition. ConclusionCategorizing patient-specific intracranial aneurysms into standard shapes viz, spherical, beehive and pear could generalize the process of prediction of hemodynamic and bio-mechanical rupture indicators. Comparative assessment of the flow field and stresses reported from the simulations on idealised models, with corresponding patient-specific simulations reveal that, these studies could aid in understanding the generalised shape dependence of hemodynamic and bio-mechanical behaviour of aneurysms.

Complete bilateral blindness associated with ruptured anterior communicating artery aneurysm: A literature review and illustrative case

Background

Anterior communicating artery (AcomA) aneurysms are considered one of the most common intracranial aneurysms, contributing to approximately 40% of the subarachnoid hemorrhages related to aneurysmal rupture. Aneurysms of the anterior circulation are commonly present with visual defects varying in their nature according to the aneurysmal site. However, complete bilateral vision loss associated with AcomA aneurysms is a significantly rare finding. We are reporting a case of complete bilateral blindness in a patient with a ruptured AcomA aneurysm with a literature review.

Methods

We conducted a PubMed Medline database search by the following combined formula of subjects' headings: (((Intracranial Aneurysm [MeSH Terms]) AND (AcomA Aneurysm [Title/Abstract])) AND [(Vision loss OR Blindness [Text Word])) AND (case reports [Filter]). Additional articles were searched through the reference lists of the included articles.

Results

Our review yielded a total of five cases. All the present cases revealed unilateral blindness only, and their outcomes after treatment vary from recovery of vision to unchanged complete vision loss - none of the cases found in the literature presented with bilateral blindness.

Conclusion

AcomA aneurysms can be associated with visual loss in some cases. However, usually, the defect is unilateral. Studies of the visual defects, including potential bilateral complete blindness associated with rupture inferiorly, directed AcomA aneurysm, should be highlighted.

Toward Grading Subarachnoid Hemorrhage Risk Prediction: A Machine Learning-Based Aneurysm Rupture Score

OBJECTIVE

Existing approaches neither provide an accurate prediction of subarachnoid hemorrhage (SAH) nor offer a quantitative comparison among a group of its risk factors. To evaluate the population, hypertension, age, size, earlier subarachnoid hemorrhage, and location (PHASES) and unruptured intracranial aneurysm treatment score (UIATS) scores and develop an Artificial Intelligence-based 5-year and lifetime aneurysmal rupture criticality prediction (ARCP) score for a set of risk factors.

METHODS

We design various location-specific and ensemble learning models to develop lifetime rupture risk, employ the longitudinal data to develop a linear regression-based model to predict an aneurysm's growth score, and use the Apriori algorithm to identify risk factors strongly associated with SAH. We develop ARCP by integrating output of Apriori algorithm and ML models and compare with PHASES and UIATS scores along with the scores of a multidisciplinary team of neurosurgeons.

RESULTS

The PHASES and UIATS scores show sensitivities of 22% and 35% and specificities of 76% and 79%, respectively. Location-specific models show precision and recall of 93% and 90% for the middle cerebral artery, 83% and 80% for the anterior communicating artery, and 80% and 80% for the supraclinoid internal carotid artery, respectively. The ensemble method shows both precision and recall of 80%. The validation of the models shows that ARCP performs better than our control group of neurosurgeons. Data-driven knowledge produces comparisons among 61 risk factor combinations, 11 ranked minor, 8 moderate, and 41 severe, and 1 of which is a critical factor.

CONCLUSIONS

The PHASES and UIATS are weak predictors, and the ARCP score can identify, and grade, risk factors associated with SAH.

Machine Learning Algorithms for Rupture Risk Assessment of Intracranial Aneurysms: A Diagnostic Meta-Analysis

OBJECTIVE

Several machine learning algorithms have been increasingly applied to predict the rupture risk of intracranial aneurysms. We performed the present diagnostic meta-analysis to comprehensively evaluate the diagnostic value of machine learning algorithms for assessing the rupture risk of intracranial aneurysms.

METHODS

We systematically searched 3 electronic databases, including Medline (via PubMed), the Cochrane Register of Controlled Trials (via Ovid), and Embase (via Elsevier), to retrieve eligible studies from the databases' inception through March 2021. The latest update was performed in June 2021. StataMP, version 14, was used to estimate all pooled diagnostic values.

RESULTS

A total of 4 studies involving 6 reports were considered to meet the inclusion criteria. Our diagnostic meta-analysis generated the following pooled diagnostic values: sensitivity, 0.84 (95% confidence interval [CI], 0.75-0.90); specificity, 0.78 (95% CI, 0.68-0.85); positive likelihood ratio, 3.8 (95% CI, 2.4-5.9); negative likelihood ratio, 0.21 (95% CI, 0.12-0.35), diagnostic odd ratio, 18 (95% CI, 7-46), and area under the summary receiver operating characteristic curve, 0.88 (95% CI, 0.85-0.90).

CONCLUSIONS

Our findings have demonstrated that the diagnostic performance of machine learning algorithms for the rupture risk assessment of AIs is excellent. Considering that the negative effects resulted from the limited number of eligible studies, we suggest developing more well-designed studies with larger sample sizes to validate our findings.

Clinical characteristics of intracranial aneurysms in elderly patents over 70 years old: a retrospective observational study

Background

Although the characteristics of intracranial aneurysms (IAs) in different age groups have been well documented, they remain relatively unclear in elderly patients due to a lack of large sample studies.

Methods

Data from IA patients aged more than 70 years who were treated in our centre from January 2016 to January 2020 were retrospectively collected.

Results

A total of 290 elderly patients (75.9% female) with a mean age of 74.0 ± 4.7 years were analysed. Rupture occurred in 60.7% of patients, 38.6% of whom presented with meningeal irritation, and seizures were noted in 2.3%. A total of 48.9% of the patients with ruptured IAs had initial symptoms presenting with slow development, and the mean delay from ictus was prolonged to 264.2 ± 914.0 hours. In addition, 61.9% of the patients with ruptured IAs had lesions with a maximum diameter of less than 5 mm. A total of 30.3% of the patients had multiple aneurysms, 35.5% had aneurysms with irregular shapes and 54.8% had cerebrovascular atherosclerotic stenosis (CAS). Pulmonary infection (n = 138, 47.6%), hydrocephalus (n = 72, 24.8%), and thrombosis (n = 35, 12.1%) were common complications during hospitalization. By the end of the 1-year follow-up, 22.1% of the patients had unfavourable clinical outcomes, and the mortality rate was 23.4%.

Conclusions

Several characteristics regarding IAs in elderly patients were reported, including an obvious female predominance; mild, slow initial symptom development causing prolonged admission delay; a low incidence of meningeal irritation and seizures due to decreased electrophysiological activity of the neurons; increased percentages of CAS, multiple aneurysms, and aneurysms with daughter sacs causing a high risk of rupture even for small lesions; a high risk of complications during hospitalization; and relatively poor clinical outcomes.

Endoscope-assisted microneurosurgery for intracranial aneurysms: A systematic review and meta-analysis

BACKGROUND

In the surgical approach to treat deep-seated intracranial lesions, endoscopes can be used to assist microsurgical operations and improve outcomes. This technique is often called endoscope-assisted microneurosurgery (EAM). This systematic review and meta-analysis aimed to evaluate the feasibility, safety, and effectiveness of EAM.

METHODS

We performed a meta-analysis of relevant articles identified using PubMed, Embase, and the Cochrane Central Register to assess the efficacy of EAM according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Primary outcomes were repositioning of the definitive clip, better surgical field, the overall and endoscope-related complication rates, mortality, and the rate of follow up.

RESULTS

A total of 10 studies of 1,432 patients with 1,717 aneurysms treated with EAM were included. EAM led to repositioning of the definitive clip in 13% (95% CI, 9%-17%; I₂ = 72.61%; p < 0.001); 77% of aneurysms treated with endoscopically assisted vision and information had a better outcome than that with standard surgery (95% CI, 52%-95%; I₂ = 97.63%; p < 0.001). There was an overall complication rate of 6% (95% CI, 1%-13%; I₂ = 91.39%; p < 0.001). The incidence of endoscope-related complications was 0% (95% CI, 0%-1%; I₂ = 64%; p < 0.001). The mortality was 0% (95% CI, 0-1%; I₂ = 0.0%); and 94% of patients had an excellent to good recovery and good outcome (95% CI, 88%-98%; I₂ = 88.42%; p < 0.001).

CONCLUSIONS

Our comprehensive study showed that EAM for intracranial aneurysms is feasible, the safety of the surgery is good, and the patients have a good prognosis, Therefore, we think EAM can be more widely adopted in the future.

Association Between Regular Blood Pressure Monitoring and the Risk of Intracranial Aneurysm Rupture: a Multicenter Retrospective Study with Propensity Score Matching

Although hypertension is a known risk factor for intracranial aneurysm rupture, the benefit of the management of blood pressure in reducing the rupture risk of intracranial aneurysms remains largely unknown, especially for regular blood pressure monitoring. We conducted a retrospective analysis of a prospectively maintained database of 3965 patients with saccular intracranial aneurysms from 20 medical centers in China. The patients were divided into the non-hypertensive group and hypertensive group. Propensity score matching was applied to identify a cohort of patients with similar baseline characteristics. Univariable and multivariable logistic regression analyses were performed to determine the association between intracranial aneurysm rupture and the management of blood pressure. After matching, hypertension was significantly associated with an increased rupture risk of intracranial aneurysms (OR = 2.559, 95%CI = 2.161-3.030, P = 0.000). For the management of blood pressure, controlled hypertension (OR = 1.803, 95%CI = 1.409-2.307, P = 0.000), uncontrolled hypertension (OR = 2.178, 95%CI = 1.756-2.700, P = 0.000), and hypertension without regular blood pressure monitoring (OR = 5.000, 95%CI = 3.823-6.540, P = 0.000) were all significantly associated with a higher rupture risk compared with the absence of hypertension. Moreover, hypertension without regular blood pressure monitoring was associated with a higher rupture risk compared with either controlled hypertension (OR = 3.807, 95%CI = 2.687-5.395, P = 0.000) or hypertension with regular blood pressure monitoring (including controlled and uncontrolled hypertension) (OR = 2.893, 95%CI = 2.319-3.609, P = 0.000). The absence of regular blood pressure monitoring was significantly associated with an increased risk of intracranial aneurysm rupture, emphasizing the importance of implementation of regular blood pressure monitoring in hypertensive patients with intracranial aneurysms.

Low-profile LEO baby stents using dual stenting technique in treating complex intracranial aneurysms located in small artery: Initial and mid-term outcome

BACKGROUND

Endovascular treatment of complex intracranial aneurysms (IAs) was challenging. Our retrospective study aimed to assess the efficacy and safety of LEO Baby stents using the dual stenting technique for complex IAs.

METHODS

Clinical and angiographic data of 15 IAs located in small arteries treated by LEO Baby stents in our neurosurgical center were retrospectively collected and analyzed between April 2019 to January 2021.

RESULTS

15 patients received dual stent-assisted coiling procedures and the stent configurations include 7 cases of T- configuration, 5 cases of parallel- configuration, 2 cases of Y- configuration, and 1case of X- configuration. 11 patients received dual stents deployment with only LEO Baby stents and 4 patients received LEO Baby stent combined with LVIS stent. Immediate postprocedural results showed Raymond I in 4 patients (26.7%), Raymond II in 5 patients (33.3%), and Raymond III in 6 patients (40.0%). One patient (6.7%) was confirmed with an ischemic complication during the procedure. All 15 patients (100%) received clinical follow-up ranging between 6 and 28 months. An mRS score of 0-2 was reached in all patients. 13 patients (86.7%) received angiographic clinical follow-up ranging between 6 and 20 months. The results revealed that Raymond I was achieved in 10 patients (76.9%) and Raymond II was achieved in 3 patients (23.1%). One patient (7.7%) in 6 months after the procedure was confirmed with asymptomatic in-stent stenosis.

CONCLUSION

This preliminary study suggests that dual stents deployment of LEO Baby stents was a feasible strategy for the treatment of complex IAs located in the small arteries.

Long term safety and effectiveness of LVIS Jr for treatment of intracranial aneurysms- a Canadian Multicenter registry

BACKGROUND

The Low-profile Visible Intraluminal Support device (LVIS Jr) has become a commonly used intracranial stent for the treatment of intracranial aneurysms. However long-term stability and effectiveness remains to be seen. The purpose of the study was to assess the long-term efficacy, safety and durability of LVIS Jr. in a retrospective multicenter registry.

METHODS

Patients with saccular aneurysms treated at centers across Canada using LVIS Jr for intracranial aneurysms were included in this retrospective registry between the dates of January 2013 and April 2019. Self reported outcomes were collected and used to assess both perioperative and long term safety and effectiveness. Both univariate and multivariate analysis were performed.

RESULTS

Total of 196 patients (132 Women; mean age of 57.6 years) underwent endovascular aneurysm treatment with at least 1 LVIS Jr. stent. Mean aneurysm dome size was 7.4 mm, and mean neck size of 4.3 mm. Mean clinical and imaging follow up were 950 and 899 days respectively. Class I/II was achieved in 85% on long term follow up. Periprocedural morbidity and mortality was 4.6% and 2% and additional delayed morbidity and mortality was 3% and 2.5%. Aneurysm size >10 mm was independent predictor of periprocedural complication (OR 2.59, p = 0.048) while an increased dome to neck ratio >1.5 was independent predictor of increased delayed complications (OR 3.99, p = 0.02).

CONCLUSION

The LVIS Jr. intracranial stent is an effective device in the treatment of intracranial aneurysms. Satisfactory long term occlusion rates can be achieved safely with stent-assisted coil embolization.

Evaluation of multimodal intraoperative neurophysiologic monitoring during supratentorial aneurysm surgery: a comparative study

The objective of this study is to determine the role of multimodal intraoperative neurophysiologic monitoring (IONM) in the overall outcome of intracranial aneurysms surgery, and the risk factors associated with ischemic complications. We grouped 268 ruptured and unruptured intracranial aneurysms surgically treated at our institution into 2 cohorts, based on the use of IONM (180; 67.16%) or non-use of IONM (88; 32.84%). The IONM technique used was multimodal: electroencephalogram (EEG), somatosensory evoked potentials (SSEPs), transcranial (TES), and direct cortical (DCS) stimulation motor evoked potentials (MEPs). There was a significant difference, with a reduction in perioperative strokes (p = 0.011) and better motor surgery-related outcome in the IONM group (p = 0.016). Independent risk factors identified for surgery ischemic complications were temporary clipping time ≥ 6'05″ (odds ratio [OR]: 3.03; 95% CI: 1.068-8.601; p = 0.037), aneurysm size ≥ 7.5 mm (OR: 2.65; 95% CI: 1.127-6.235; p = 0.026), and non-use of IONM (OR: 2.79; 95% CI: 1.171-6.636; p = 0.021). Conversely, aneurysm rupture was not detected as an independent risk factor (OR: 2.5; 95% CI: 0.55-4.55; p = 0.4). Longer temporary clipping time, larger aneurysm size, and the non-use of IONM could be considered as risk factors for ischemic complications during microsurgical clipping. A standardized designed protocol including multimodal IONM with DCS provides continuous information about blood supply and allows reduction of treatment-related morbidity. Multimodal IONM is a valuable technique in intracranial aneurysm surgery.

Update on Clinical Management with Neurovascular Stents

Endovascular stenting has continued to evolve given the new trials. Several new stents have recently been developed to address specific purposes. In this focused review, we discuss the concepts of neurointerventional stents and address the clinical implications. Furthermore, each type of stent is discussed with supporting evidence for clinical utility. In the final component, we argue for continued development and utilization.

Comprehensive mass spectrometry for development of proteomic biomarkers of intracranial aneurysms

Protein biomarkers of intracranial aneurysm (IA) are essential for early detection and prediction of its rupture to facilitate the diagnosis and clinical management of the disease, monitor treatment response and detect recurrence. Here, we developed a comprehensive strategy for IA biomarker discovery by analyzing tissues from an animal model (n = 4) and serum from human patients (n = 60) using isobaric tandem mass tags-based quantitative proteomics. A total of 4811 and 562 proteins were identified from aneurysm tissue and serum samples, respectively. The 223 candidate protein biomarkers were further validated in an independent serum cohort (n = 30) by multiple reaction monitoring analysis. Combined with a logistic regression model, we built a diagnostic classifier P2 (FCN2 & RARRES2) to differentiate IA from healthy controls with accuracy of 93.3%, as well as a diagnostic classifier P7 (ADAM12, APOL3, F9, C3, CEACAM1, ICAM3, KLHDC7A) to classify ruptured IA from unruptured IA with accuracy of 95.0%. Taken together, our results suggest a valuable strategy for biomarker discovery and patient stratification in IA.

The diagnostic accuracy of MRI in determining the relations between paraclinoid aneurysms and the cavernous sinus

Purpose

The location of paraclinoid aneurysms is determinant for evaluation of its intradural compartment and risk of SAH after rupture. Advanced MRI techniques have provided clear visualization of the distal dural ring (DDR) to determine whether an aneurysm is intracavernous, transitional or intradural for decision-making. We analyzed the diagnostic accuracy of MRI in predicting whether a paraclinoid aneurysm is intracavernous, transitional or intradural.

Methods

We conducted a prospective cohort between January 2014 and December 2018. Patients with paraclinoid aneurysms underwent 3D fast spin-echo MRI sequence before surgical treatment. The DDR was the landmark for MRI characterization of the aneurysms as follow: (i) Intradural; (ii) Transitional; and (iii) Intracavernous. The MRI sensitivity, specificity, positive and negative likelihood ratios were determined compared to the intraoperative findings. We also evaluated the intertechnique agreement using the Cohen’s kappa coefficient (κ) for dichotomous classifications (cavernous vs non-cavernous).

Results

Twenty patients were included in the cohort. The accuracy of MRI showed a sensitivity of 86.7% (95%CI:59.5–98.3) and specificity of 90.0% (95%CI:55.5–99.8). Analyzing only patients without history of SAH, accuracy test improved with a sensitivity of 92.3% (95%CI:63.9–99.8) and specificity reached 100% (95%CI: 63–100). Values of Cohen’s kappa (κ), intertechnique agreement was considered substantial for dichotomous classifications (κ = 0.754; p < 0.001). For patients without previous SAH, intertechnique agreement was even more coincident for the dichotomous classification (κ = 0.901; p < 0.001).

Conclusion

3D fast spin-echo MRI sequence is a reliable and useful technique for determining the location of paraclinoid aneurysms in relation to the cavernous sinus, particularly for patients with no history of SAH.

Enhanced Radiomics for Prediction of Rupture Status in Cerebral Aneurysms

BACKGROUND

Radiomics is a powerful tool for automatic extraction of morphological features, but when applied to cerebral aneurysms, it is inferior to established descriptors in classifying rupture status. We sought a strategy to recover neck orientation and parent vessel caliber to enhance Radiomics performance and facilitate its adoption for aneurysm risk stratification.

METHODS

We analyzed 135 sidewall (32 ruptured) and 216 bifurcation (90 ruptured) aneurysms from three-dimensional rotational catheter angiography datasets. Clinical three-dimensional rotational catheter angiography defined in arbitrary orientation underwent affine transformations enabling aneurysm neck alignment to XY plane before analysis in PyRadiomics, facilitating automatic extraction of aneurysm height and width, previously not possible with random alignment. Additionally, parent vessel size was estimated from aneurysm location and incorporated into enhanced Radiomics (height, width, height/width, size ratio). Rupture status classification was compared across methodologies for 31 automatically computed conventional Radiomics, enhanced Radiomics, and established size/shape descriptors using univariate, multivariate, and area under the curve (AUC) statistics.

RESULTS

Enhanced Radiomics-derived height/width and size ratio were significantly higher in both ruptured subsets. Using multivariate analysis in sidewall lesions, enhanced Radiomics (AUC = 0.85) matched established features (AUC = 0.86) and outperformed conventional Radiomics (AUC = 0.82); in bifurcation lesions, enhanced Radiomics (AUC = 0.78) outperformed both established features (AUC = 0.76) and conventional Radiomics (AUC = 0.74).

CONCLUSIONS

Enhanced Radiomics incorporating neck orientation and parent vessel estimate is an efficient operator-independent methodology that offers superior rupture status classification for both sidewall and bifurcation aneurysms and should be considered a strong candidate for larger-scale multicenter and multimodality validation.

Moments of Intra-Dome Velocity Distribution as Robust Predictors of Rupture Status in Cerebral Aneurysms

BACKGROUND

Wall shear stress (WSS), the spatial gradient of flow velocity at luminal surface, has been employed for aneurysmal hemodynamic analysis, but it is sensitive to surface irregularities and noise. We devised a volumetric approach to evaluate discriminant power of intra-dome flow velocity distribution and modal analysis in rupture status determination compared with previously described WSS analysis.

METHODS

Catheter three-dimensional rotational angiographic datasets matched for volume were segmented in 20 sidewall aneurysms (10 ruptured), computational fluid dynamics simulations were performed, and velocity distributions were extracted from mesh-independent isometric sampling followed by moment analysis (mean, variance, skewness, and kurtosis). Univariate and multivariate analysis was used to evaluate discriminant performance of velocity moments. Sensitivity of velocity moments and WSS was evaluated to bleb presence and surface irregularity using digital bleb removal and surface noise addition.

RESULTS

Velocity moments of ruptured aneurysms showed higher skewness (2.45 ± 0.57 vs. 1.36 ± 0.82, P = 0.003) and kurtosis (11.83 ± 4.77 vs. 6.05 ± 4.65, P = 0.01) with lower mean (0.019 ± 0.01 vs. 0.038 ± 0.02, P = 0.03) compared with unruptured lesions; in multivariate modeling, skewness alone emerged as best predictor (area under the curve = 0.88). Bleb removal increased low WSS by 548%, and surface noise decreased it by 85.8% while having a smaller (<7%) effect on velocity skewness and kurtosis.

CONCLUSIONS

High aneurysm dome flow velocity skewness and kurtosis suggest an exponential distribution in ruptured lesions, with high peaks at low velocities, consistent with areas of slow flow. In contrast to WSS-based techniques, this approach is robust against surface variations, with promising improved rupture status discriminant performance that requires further validation in expanded future studies.

Development and assessment of machine learning models for predicting recurrence risk after endovascular treatment in patients with intracranial aneurysms

Intracranial aneurysms (IAs) remain a major public health concern and endovascular treatment (EVT) has become a major tool for managing IAs. However, the recurrence rate of IAs after EVT is relatively high, which may lead to the risk for aneurysm re-rupture and re-bleed. Thus, we aimed to develop and assess prediction models based on machine learning (ML) algorithms to predict recurrence risk among patients with IAs after EVT in 6 months. Patient population included patients with IAs after EVT between January 2016 and August 2019 in Hunan Provincial People's Hospital, and an adaptive synthetic (ADASYN) sampling approach was applied for the entire imbalanced dataset. We developed five ML models and assessed the models. In addition, we used SHapley Additive exPlanations (SHAP) and local interpretable model-agnostic explanation (LIME) algorithms to determine the importance of the selected features and interpret the ML models. A total of 425 IAs were enrolled into this study, and 66 (15.5%) of which recurred in 6 months. Among the five ML models, gradient boosting decision tree (GBDT) model performed best. The area under curve (AUC) of the GBDT model on the testing set was 0.842 (sensitivity: 81.2%; specificity: 70.4%). Our study firstly demonstrated that ML-based models can serve as a reliable tool for predicting recurrence risk in patients with IAs after EVT in 6 months, and the GBDT model showed the optimal prediction performance.

Multiple overlapping stent-assisted coiling improves efficacy and safety of treatment for complex intracranial aneurysms: a randomized trial

BACKGROUND

Intracranial aneurysm rupture is the main cause of subarachnoid hemorrhage, leading to high disability and mortality. This study aimed to evaluate the clinical treatment effects of multiple overlapping stent-assisted coiling for complex intracranial aneurysms.

METHODS

We conducted a randomized, controlled, single-blinded clinical trial among 168 patients diagnosed with complex intracranial aneurysms. Treatment allocation to either single stent (SS) group or multiple stent (MS) group was randomized at 1:1 ratio using a Web-based platform. The O'Kelly-Marotta (OKM) grading scale was used to evaluate the degree of aneurysm occlusion after operation and during follow-up. Good aneurysm occlusion was defined as OKM grade C-D. The modified Rankin Scale (mRS) was used to evaluate the neurological status and the clinical outcome of patients.

RESULTS

Efficacy comparative analysis demonstrated that major recurrence of aneurysms was significantly reduced in the MS group (P = 0.012). In addition, the MS group displayed significantly reduced number of patients with mRS between 3 and 6 (P = 0.007) and increased number of patients with mRS between 0 and 1 (P = 0.034). Furthermore, the MS group showed increased percentage of patients with OKM grade C-D (P = 0.041). Compared with the SS group, the MS group exhibited decreased mortality (P = 0.037) and morbidity (P = 0.035).

CONCLUSIONS

Multiple overlapping stent-assisted coiling significantly improved the clinical treatment effects and provided a new method for complex intracranial aneurysms.

Post-traumatic intracranial pseudo-aneurysms of posterior circulation: a comprehensive review of an under-diagnosed and rare entity

Traumatic aneurysms are rare and the total number of cases involving the posterior circulation (TIPC) is even smaller. Traumatic brain injury (TBI) may be responsible not only of rupture in brain aneurysm (BrA) pre-existing to trauma, but it has been identified also as a possible pathogenetic cause of TIPC formation in patients not affected by intracranial vascular lesions. A complete literature review was performed of all reported cases regarding rupture of BrA with SAH resulting from TIPC not previously identified at the first radiological screening. A representative case of a left posterior inferior cerebellar artery (PICA) pseudo-aneurysm caused by left vertebral artery’s dissection is reported. We show a unique complete collection of all 34 cases. Despite their rarity, TIPCs are associated with a significant morbidity and mortality rate, as high as 40–60%. Of the 22 patients with good neurological status (64.7%), we did not notice a significant correlation with regard to the location of the aneurysm, type of treatment, or clinical onset. Early recognition of a pseudo-aneurysm and adequate treatment seem to be the most important prognostic factor for these patients. Despite their rarity, TIPCs are associated with a significant morbidity and mortality rate. A TIPC should be suspected in case of delayed deterioration in head‐injured patient and should be investigated with angiography. Conservative management is worsened by poor prognosis and the goal of treatment is to exclude the aneurysm from circulation with surgical or endovascular methods as soon as possible.

MedmeshCNN - Enabling meshcnn for medical surface models

BACKGROUND AND OBJECTIVE

MeshCNN is a recently proposed Deep Learning framework that drew attention due to its direct operation on irregular, non-uniform 3D meshes. It outperformed state-of-the-art methods in classification and segmentation tasks of popular benchmarking datasets. The medical domain provides a large amount of complex 3D surface models that may benefit from processing with MeshCNN. However, several limitations prevent outstanding performances on highly diverse medical surface models. Within this work, we propose MedMeshCNN as an expansion dedicated to complex, diverse, and fine-grained medical data.

METHODS

MedMeshCNN follows the functionality of MeshCNN with a significantly increased memory efficiency that allows retaining patient-specific properties during processing. Furthermore, it enables the segmentation of pathological structures that often come with highly imbalanced class distributions.

RESULTS

MedMeshCNN achieved an Intersection over Union of 63.24% on a highly complex part segmentation task of intracranial aneurysms and their surrounding vessel structures. Pathological aneurysms were segmented with an Intersection over Union of 71.4%.

CONCLUSIONS

MedMeshCNN enables the application of MeshCNN on complex, fine-grained medical surface meshes. It considers imbalanced class distributions derived from pathological findings and retains patient-specific properties during processing.

MR Brain Screening in ADPKD Patients : To Screen or not to Screen?

BACKGROUND

Adult polycystic kidney disease (ADPKD) still represents a major cause of renal failure and intracranial aneurisms (IA) have a higher prevalence in ADPKD than in the general population. Current guidelines suggest performing brain MRI only in the subjects with a positive familiar history of IAs or subarachnoid hemorrhage (SAH). This is a retrospective case-control analysis to evaluate the usefulness of a MR screening program in ADPKD patients.

METHODS

We retrospectively analyzed all ADPKD patients followed in our outpatient clinic between 2016 and 2019 who underwent a brain MRI screening. We evaluated the presence of IAs and others brain abnormalities and compared our results with a non-ADPKD population (n = 300). We performed univariate and multivariate regression analysis to evaluate if general and demographic features, laboratory findings, clinical parameters and genetic test results correlated with IAs or other brain abnormalities presence.

RESULTS

Among the patients evaluated 17 out of 156 (13.6%) ADPKD patients had IAs, compared to 16 out of 300 (5.3%) non-ADPKD controls (p < 0.005). Considering ADPKD patients presenting IAs, 12 (70.6%) had no family history for IAs or SAH. Genetic analysis was available for 97 patients: in the sub-population with IAs, 13 (76.5%) presented a PKD1 mutation and none a PKD2 mutation. We found that arachnoid cysts (AC) (p < 0.001) and arterial anatomical variants (p < 0.04) were significantly more frequent in ADPKD patients.

CONCLUSION

In our population ADPKD patients showed a higher prevalence of IAs, AC and arterial variants compared to non-ADPKD. Most of the IAs were found in patients presenting a PKD1 mutation. We found a significant number of alterations even in those patients without a family history of IAs or SAH. The practice of submitting only patients with familial IAs or kidney transplantation candidates to MRI scan should be re-evaluated.

Luminal enhancement in intracranial aneurysms: fact or feature?-A quantitative multimodal flow analysis

Purpose

Intracranial aneurysm (IA) wall enhancement on post-contrast vessel wall magnetic resonance imaging (VW-MRI) is assumed to be a biomarker for vessel wall inflammation and aneurysm instability. However, the exact factors contributing to enhancement are not yet clarified. This study investigates the relationship between luminal enhancement and intra-aneurysmal flow behaviour to assess the suitability of VW-MRI as a surrogate method for determining quantitative and qualitative flow behaviour in the aneurysm sac.

Methods

VW-MRI signal is measured in the lumen of three patient-specific IA flow models and compared with the intra-aneurysmal flow fields obtained using phase-contrast magnetic resonance imaging (PC-MRI) and computational fluid dynamics (CFD). The IA flow models were supplied with two different time-varying flow regimes.

Results

Overall, the velocity fields acquired using PC-MRI or CFD were in good agreement with the VW-MRI enhancement patterns. Generally, the regions with slow-flowing blood show higher VW-MRI signal intensities, whereas high flow leads to a suppression of the signal. For all aneurysm models, a signal value above three was associated with velocity values below three cm/s.

Conclusion

Regions with lower enhancements have been correlated with the slow and high flow at the same time. Thus, further factors like flow complexity and stability can contribute to flow suppression in addition to the flow magnitude. Nevertheless, VW-MRI can qualitatively assess intra-aneurysmal flow phenomena and estimate the velocity range present in the corresponding region.

Factors affecting resolution of oculomotor nerve palsy following endovascular embolization of posterior communicating artery aneurysms

PURPOSE

To investigate the effect of endovascular embolization of posterior communicating artery (Pcom) aneurysms on concomitant oculomotor nerve palsy (OMNP) and factors affecting the effect of treatment.

MATERIALS AND METHODS

Patients with the Pcom aneurysms concomitant with OMNP were retrospectively enrolled for endovascular treatment of the aneurysms. All patients had the endovascular management. The clinical effect, degree of OMNP, size of the aneurysm, type of treatment, subarachnoid hemorrhage (SAH), and time from onset to treatment were analyzed on the resolution of OMNP.

RESULTS

Ninety-six patients with 99 Pcom aneurysms were enrolled and treated endovascularly, with the success rate of 100%. Immediately after endovascular treatment, 75 aneurysms (75.75%) got complete occlusion, and 24 (24.24%) nearly complete occlusion. Followed up for 3-18 (mean 8.52±0.56) months, complete resolution of the OMNP was achieved in 63 patients (65.63%), partial resolution in 21 (21.88%), and non-recovery in the other 12 (12.50%). The degree of OMNP at onset, SAH, and time from onset to treatment were significantly (P<0.05) correlated with the resolution of OMNP. Univariate analysis revealed that younger age of the patient, degree of OMNP at onset, presence of subarachnoid hemorrhage, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP. Multivariate analysis revealed that the younger age, degree of OMNP at onset, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP.

CONCLUSION

Endovascular embolization of Pcom aneurysms concomitant with OMNP can effectively improve the OMNP symptoms, especially for patients with moderate and a shorter history of OMNP. Younger age, degree of oculomotor nerve palsy at onset, and time from onset to treatment may significantly affect recovery of oculomotor nerve palsy.

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 factors for periprocedural ischemic stroke following endovascular treatment of intracranial aneurysms

Background

The aim of this study was to comprehensively evaluate the risk factors of periprocedural ischemic stroke associated with endovascular treatment of intracranial aneurysms using a real-world database.

Methods

From August 2016 to March 2017, 167 patients were enrolled. Univariate analysis and multivariate logistic regression analysis were used to examine the risk factors for periprocedural ischemic stroke.

Results

Among the 167 cases, periprocedural ischemic stroke occurred in 20 cases (11.98%). After univariate analysis, the ischemic group had a higher proportion of large (≥ 10 mm) aneurysms than the control group (45.0% vs. 23.1%, p = 0.036). The incidence of periprocedural ischemic stroke was higher in cases treated by flow diverter (21.6%) or stent-assisted coiling (11.8%) than in cases treated by coiling only (2.7%), and the differences were statistically significant (p = 0.043). After multivariate logistic regression analysis, treatment modality was the independent risk factor for periprocedural ischemic stroke. Compared with the coiling-only procedure, flow diverter therapy was associated with a significantly higher rate of periprocedural ischemic stroke (OR 9.931; 95% CI 1.174–84.038; p = 0.035).

Conclusions

Aneurysm size and treatment modality were associated with periprocedural ischemic stroke. Larger aneurysms were associated with increased risk of periprocedural ischemic stroke. Flow diverter therapy was associated with significantly more periprocedural ischemic stroke than the coiling procedure alone.

Longitudinal Cost Profiles of Pipeline Embolization Device Versus Stent-Assisted Coiling in Propensity-Matched Unruptured Small Anterior Circulation Aneurysms

BACKGROUND

The cost profiles of stent-assisted coiling (SAC) vs Pipeline embolization device (PED) in small unruptured anterior circulation aneurysms have not been studied.

OBJECTIVE

To compare the 2 modalities cost profiles in a propensity-matched cohort controlling for potential technical complexity confounders including size and location.

METHODS

Patients treated with either SAC or PED at our institution were identified. Following propensity-score algorithm, 46 patients, 23 in each group were matched. The procedural and follow-up costs in each group were analyzed and compared.

RESULTS

Median maximal aneurysm size in the SAC and PED cohort were 5.3 vs 5.1 mm, respectively. Costs of access guide materials were significantly higher in the SAC group (P < .01). The average implant cost was not significantly different between the SAC and PED cohorts (${\$}$13973.2 ± ${\$}$2886.2 vs ${\$}$14,760.7 ± ${\$}$3782.1, respectively; P = .43). Similarly, total procedural costs were not different (${\$}$18341.5 ± 4104 vs ${\$}$17484.3 ± 2914.1, respectively, P = .42). Although there were significantly more total follow-ups (P = .02) and longer follow-up duration (P = .01) in SAC cohort, no significant difference in follow-up costs between the 2 groups was identified (${\$}$20557 ± ${\$}$9247 vs ${\$}$18958 ± ${\$}$9171.9, P = .56). Overall cost was similar between the SAC (${\$}$38898.9 ± ${\$}$9645.5) and PED groups (${\$}$36442.4 ± ${\$}$9076) (P = .38).

CONCLUSION

In small unruptured anterior circulation aneurysms (excluding anterior communicating artery aneurysms) matched for technical complexity confounders, SAC and PED offer an overall equivalent economic cost profile. Postprocedural noninvasive imaging was more frequent in the SAC group. However, follow-up costs and total costs were not significantly different.

Hemodynamic factor evaluation using computational fluid dynamics analysis for de novo bleb formation in unruptured intracranial aneurysms

Background

Although bleb formation increases the risk of rupture of intracranial aneurysms, previous computational fluid dynamic (CFD) studies have been unable to identify robust causative hemodynamic factors, due to the morphological differences of prebleb aneurysm models and a small number of aneurysms with de novo bleb formation. This study investigated the influences of differences in the aneurysm-models and identify causative hemodynamic factors for de novo bleb formation.

Materials and methods

CFD analysis was conducted on three aneurysm models, actual prebleb, postbleb, and virtual prebleb models of two unruptured aneurysms with de novo bleb formation. A new multipoint method was introduced in this study. We evenly distributed points with a 0.5-mm distance on the aneurysm surface of the actual prebleb models (146 and 152 points in the individual aneurysm, respectively), and we statistically compared hemodynamics at the points in the areas with and without bleb formation (19 and 279 points, respectively).

Results

Visually, blebs formed on an aneurysm surface area with similar hemodynamic characteristics in the actual and virtual prebleb models. Statistical analysis using the multipoint method revealed that the de novo bleb formation area was significantly correlated with high pressure (p < 0.001), low wall shear stress (WSS) (p < 0.001), and the center of divergent WSS vectors (p = 0.025).

Conclusions

De novo bleb formation in intracranial aneurysms may occur in areas associated with the combination of high pressure, low WSS, and the center of divergent WSS vectors. The multipoint method is useful for statistical analysis of hemodynamics in a limited number of aneurysms.

Demographic and anatomical comparison of ruptured and unruptured intracranial aneurysms: a case control study

BACKGROUND

Our understanding of the pathophysiology and management of intracranial aneurysms (IAs) continuously advances. This case-control study analyzed the demographics of patients with IAs and the morphological Digital Subtraction Angiography (DSA) characteristics of ruptured and unruptured IAs.

METHODS

Two patient groups with saccular ruptured and unruptured IAs eligible for coiling were prospectively analyzed during a 3-year period. Patient groups were compared regarding gender, age, arterial vasculature side, anatomical location, diameter, preoperative DSA appearance, aneurysmal and anatomical Circle of Willis variations (CWV) co-existence.

RESULTS

One hundred and three patients with ruptured and eighty-six patients with unruptured IAs were studied. Anterior communicating and internal carotid artery IAs were the dominant locations: 42.7 % and 23.3 % in ruptured and 29 % and 41.9 % in unruptured IAs, respectively. The female-to-male ratio was 1.78 in ruptured and 2.44 in unruptured IAs (p =0.317), while the rupture was more frequent in younger patients (p =0.034). Angiographically, smaller diameter (p =0.01), abnormal morphology (p =0.0001), and co-existence of CWV (p =0.016) were reported in ruptured IAs. Location at bifurcation/trifurcation (p =0.487) and the co-existence of additional or mirror IA did not differ significantly (p =0.879).

CONCLUSIONS

On DSA, ruptured and unruptured IAs differed in size, morphology, and co-existence of CWV; findings that may favor the treatment of specific unruptured IAs. However, a higher level of evidence is needed to include all these factors in the treatment decision process, provide patient-oriented treatment and reliably identify unruptured IAs at greater risk. HIPPOKRATIA 2021, 25 (3):100-107.

Flow redirection endoluminal device (FRED) for treatment of intracranial aneurysms: A systematic review

INTRODUCTION

The Flow Redirection Endoluminal Device (FRED; MicroVention) is a dual-layered flow diverter used for the treatment of intracranial aneurysms. The objective of this systematic review was to compile device-related safety and effectiveness data.

METHODS

The literature from January 1, 2013 to April 30, 2021 was searched for studies describing use of the FRED for intracranial aneurysm treatment irrespective of aneurysm location and morphology. The review included anterior and posterior circulation ruptured and unruptured saccular, fusiform or dissection, and blister aneurysms. MeSH terms related to "flow re-direction endoluminal device" and "FRED for aneurysms" were used. Data related to indication, complications, and rates of aneurysm occlusion were retrieved and analyzed.

RESULTS

Twenty-two studies with 1729 intracranial aneurysms were included in this review. Overall reported morbidity was 3.9% (range 0-20%). Overall procedure-related mortality was 1.4% (range 0-6%). Complication rates fell into 5 categories: technical (3.6%), ischemic (3.8%), thrombotic or stenotic (6%), hemorrhagic (1.5%), and non-neurological (0.8%). The aneurysm occlusion rate between 0 and 3 months (reported in 11 studies) was 47.8%. The occlusion rate between 4 and 6 months (reported in 14 studies) was 73.8%. Occlusion rates continued to increase to 75.1% at 7-12 months (reported in 10 studies) and 86.6% for follow-up beyond 1 year (reported in 10 studies).

CONCLUSION

This review indicated that the FRED is a safe and effective for the treatment of intracranial aneurysms. Future studies should directly compare the FRED with other flow diverters for a better understanding of comparative safety and effectiveness among the different devices.

SDF-1α/CXCR4 Pathway Mediates Hemodynamics-Induced Formation of Intracranial Aneurysm by Modulating the Phenotypic Transformation of Vascular Smooth Muscle Cells

The objective of this study is to explore the role of the SDF-1α/CXCR4 pathway in the development of intracranial aneurysm (IA) induced by hemodynamic forces. We collected 12 IA and six superficial temporal artery samples for high-throughput sequencing, hematoxylin and eosin staining, and immunohistochemistry to examine vascular remodeling and determine the expression of the components of the SDF-1α/CXCR4 pathway, structural proteins (α-SMA and calponin) of vascular smooth muscle cells (VSMCs), and inflammatory factors (MMP-2 and TNF-α). Computational fluid dynamics (CFD) was used for hemodynamic analysis. Mouse IA model and dynamic co-culture model were established to explore the mechanism through which the SDF-1α/CXCR4 pathway regulates the phenotypic transformation of VSMCs in vivo and in vitro. We detected a significant elevation of SDF-1α and CXCR4 in IA, which was accompanied by vascular remodeling in the aneurysm wall (i.e., the upregulation of inflammatory factors, MMP-2 and TNF-α, and the downregulation of contractile markers, α-SMA and calponin). In addition, hemodynamic analysis revealed that compared with unruptured aneurysms, ruptured aneurysms were associated with lower wall shear stress and higher MMP-2 expression. In vivo and in vitro experiments showed that abnormal hemodynamics could activate the SDF-1α/CXCR4, P38, and JNK signaling pathways to induce the phenotypic transformation of VSMCs, leading to IA formation. Hemodynamics can induce the phenotypic transformation of VSMCs and cause IA by activating the SDF-1α/CXCR4 signaling pathway.

PKD1-Associated Arachnoid Cysts in Autosomal Dominant Polycystic Kidney Disease

OBJECTIVES

the prevalence of intracranial aneurysms and arachnoid cysts is higher in patients with autosomal dominant polycystic kidney disease (ADPKD) than in the general population. A genotype correlation was reported for intracranial aneurysms, but it is unclear for arachnoid cysts. Therefore, the genotype correlation with intracranial aneurysms and arachnoid cysts was investigated in ADPKD.

MATERIALS AND METHODS

intracranial aneurysms and arachnoid cysts were screened by magnetic resonance imaging (MRI), and PKD genotypes were examined using next-generation sequencing for 169 patients with ADPKD.

RESULTS

PKD1-, PKD2- and no-mutation were identified in 137, 24 and 8 patients, respectively. Intracranial aneurysms and arachnoid cysts were found in 34 and 25 patients, respectively, with no significant difference in frequency. Genotype, sex, estimated glomerular filtration rate and age at ADPKD diagnosis significantly affected the age at brain MRI. The proportional hazard risk analyzed using the age at brain MRI adjusted by these four variables was 5.0-times higher in the PKD1 group than in the PKD2 group for arachnoid cysts (P = 0.0357), but it was not different for intracranial aneurysms (P = 0.1605). Arachnoid cysts were diagnosed earlier in the PKD1 group than in the PKD2 group (54.8 vs 67.7 years, P = 0.0231), but no difference was found for intracranial aneurysms (P = 0.4738) by Kaplan-Meier analysis.

CONCLUSIONS

this study demonstrated the correlation between arachnoid cysts and PKD1 mutation. The reported association of arachnoid cysts with advanced renal disease may be due to the common correlation of these factors with PKD1 mutation.

Third Nerve Palsy Due to Intracranial Aneurysms and Recovery after Endovascular Coiling

INTRODUCTION

The modality of treatment of third nerve palsy (TNP) associated with intracranial aneurysms remains controversial. While treatment varies with the location of the aneurysm, microsurgical clipping of PComm aneurysms has generally been the traditional choice, with endovascular coiling emerging as a reasonable alternative.

METHODS

Patients with TNP due to an intracranial aneurysm who subsequently underwent treatment at a mid-sized Canadian neurosurgical center over a 15-year period (2003-2018) were examined.

RESULTS

A total of 616 intracranial aneurysms in 538 patients were treated; the majority underwent endovascular coiling with only 24 patients treated with surgical clipping. Only 37 patients (6.9%) presented with either a partial or complete TNP and underwent endovascular embolization; of these, 17 presented with a SAH secondary to intracranial aneurysm rupture. Aneurysms associated with TNP included PComm (64.9%), terminal ICA (29.7%), proximal MCA (2.7%), and basilar tip (2.7%) aneurysms. In general, smaller aneurysms and earlier treatment were provided for patients for ruptured aneurysms with a shorter mean interval to TNP recovery. In the endovascularly treated cohort initially presenting with TNP, seven presented with a complete TNP and the remaining were partial TNPs. TNP resolved completely in 20 patients (55.1%) and partially in 10 patients (27.0%). Neither time to coiling nor SAH at presentation were significantly associated with the recovery status of TNP.

CONCLUSION

Endovascular coil embolization is a viable treatment modality for patients presenting with an associated cranial nerve palsy.

Correlation Between Vascular Geometry Changes and Long-Term Outcomes After Enterprise Stent Deployment for Intracranial Aneurysms Located on Small Arteries

BACKGROUND

Enterprise stents are widely used for intracranial aneurysms located on small arteries (<2.5 mm in diameter) and change the geometry of parent arteries. The purpose of this study was to investigate the correlation between vascular geometry changes and long-term outcomes.

METHODS

Between May 2013 and 2018, 1065 consecutive intracranial aneurysms were treated with Enterprise stents at our institution. After inclusion and exclusion criteria were applied, 377 aneurysms with >6 months of digital subtraction angiography follow-up were evaluated. The cohort comprised 101 aneurysms located on small parent arteries. After stent-assisted coiling, the vascular geometry parameters of small parent arteries were compared to explore their correlation with procedural complications, delayed stent migration, and recanalization.

RESULTS

The rate of delayed aneurysm occlusion in patients with initial efferent artery diameter (De) <2.5 mm was significantly higher than in patients with De >2.5 mm (62.2% vs. 40.2%; P = 0.032). At follow-up, vascular geometry parameters significantly increased (P < 0.001). In multivariate analyses, larger aneurysms and initial parent artery angle (α) <90° were independent predictors of procedural complications and discrepancy in vessel size (ΔD) >0.5 mm was an independent predictor of delayed stent migration. Larger aneurysms and follow-up angle change (ΔAngle) <30° were independent predictors for recanalization of aneurysms located on small arteries.

CONCLUSIONS

Enterprise stent-assisted coiling of intracranial aneurysms located on small arteries is safe and effective. Our study found that Enterprise deployment in small arteries had a low procedural complication rate and high stent tolerance. Vascular geometry changes play an important role in aneurysm recanalization.

L-Arginine reduces downstream vascular contractility after flow-diverting device deployment: A preliminary study in a rabbit model

BACKGROUND

Flow diverters (FDs) are an effective treatment for intracranial aneurysms, though not free from hemorrhagic complications. A previous study demonstrated increased vascular contractility after FD-implantation as a potential mechanism of distal complications. Our study aimed to investigate whether L-arginine medication affects vascular contractility following FD deployment in a rabbit model.

METHODS

FDs were implanted in the aorta of normal rabbits (+FD, n = 10), with sham-operated aorta as controls (n = 5). L-Arginine was given in the drinking water (2.25% L-arginine hydrochloride) of half of the +FD animals (+FD/+Arg). Force contraction vascular contractility studies were performed on the aortic rings proximal and distal to the FD using an organ bath. Total eNOS, eNOS(pS1177), eNOS(pT495), COX-2, and S100A4 were quantified by western analysis on total protein lysates from aortic segments, normalizing to GAPDH.

RESULTS

Mean vascular contractility was 53% higher in distal relative to proximal aortic segments (P = 0.0038) in +FD animals, but were not significantly different in +FD/+Arg animals, or in sham-operated controls. The +FD animals expressed significantly reduced levels of eNOS(pS1177) than sham-operated controls (P = 0.0335), while both the +FD and +FD/+Arg groups had reduced levels of eNOS(pT495) relative to sham-operated controls (P = 0.0331 and P = 0.0311, respectively).

CONCLUSION

These results suggest that L-arginine medication reduces distal vascular contractility after FD treatment via nitric oxide production and thus might mitigate risk for downstream complications.

Correlation of periodontal diseases with intracranial aneurysm formation: novel predictive indicators

Background

We investigated whether periodontal diseases, specifically, periodontitis and gingivitis, could be risk factors of the incidence of intracranial aneurysms (IAs).

Methods

We performed a case–control study to compare the differences in the periodontal disease parameters of 281 cases that were divided into the IAs group and non-IAs group. All cases underwent complete radiographic examination for IAs and examination for periodontal health.

Results

Comparing with those in the non-IAs group, the cases in the IAs group were older (53.95 ± 8.56 vs 47.79 ± 12.33, p < 0.001) and had a higher incidence of hypertension (76 vs 34, p = 0.006). Univariate logistic regression analysis revealed that age (> 50 years) and hypertension were predictive risk factors of aneurysm formation (odds ratio [OR] 1.047, 95% confidence interval [95% CI] 1.022–1.073, p < 0.001 and OR 2.047, 95% CI 1.232–3.401, p = 0.006). In addition, univariate and multivariate logistic regression analyses showed that the parameters of periodontal diseases, including gingival index, plaque index, clinical attachment loss, and alveolar bone loss, were significantly associated with the occurrence of IAs (all p < 0.05). For further statistical investigation, the parameters of periodontal diseases were divided into four layers based on the quartered data. Poorer periodontal health condition (especially gingival index > 1.1 and plaque index > 1.5) had the correlation with IAs formation (p = 0.007 and p < 0.001).

Conclusion

Severe gingivitis or periodontitis, combining with hypertension, is significantly associated with the incidence of IAs.

Endovascular management of large and giant intracranial aneurysms: Experience from a tertiary care neurosurgery institute in India

Objective

With the development of endovascular technique and devices, large and giant intracranial aneurysms are increasingly being managed by this less invasive method. Here we discuss our experience on managing such aneurysms via endovascular technique.

Methods

Retrospective data on 42 patients with large and giant intracranial aneurysms managed by endovascular techniques between September 2015 to December 2017 at our neurosurgery institute were included in this analysis.

Results

There were a total 42 patients with 9 giant and 33 large aneurysms in this study. Eight aneurysms were treated by parent vessel occlusion, 22 aneurysms with coils and rest 12 aneurysms were treated with stent assisted coiling. Following the procedure, Raymond class I occlusion was accomplished in 31 (73.8%) patients while class Ⅱ in 9 (21.4%) and class Ⅲ in 2 (4.8%) patients. Overall morbidity and mortality were 9.5% and 14.3% respectively and favorable outcome was seen in 80.9% patients. Significant correlation was observed with clinical outcome and initial neurological status.

Conclusions

The study indicates that endovascular intervention is a safe and effective method in managing large and giant intracranial aneurysms with lesser morbidity and mortality.

The association between hemodynamics and wall characteristics in human intracranial aneurysms: a review

Hemodynamics plays a key role in the natural history of intracranial aneurysms (IAs). However, studies exploring the association between aneurysmal hemodynamics and the biological and mechanical characteristics of the IA wall in humans are sparse. In this review, we survey the current body of literature, summarize the studies' methodologies and findings, and assess the degree of consensus among them. We used PubMed to perform a systematic review of studies that explored the association between hemodynamics and human IA wall features using different sources. We identified 28 publications characterizing aneurysmal flow and the IA wall: 4 using resected tissues, 17 using intraoperative images, and 7 using vessel wall magnetic resonance imaging (MRI). Based on correlation to IA tissue, higher flow conditions, such as high wall shear stress (WSS) with complex pattern and elevated pressure, were associated with degenerated walls and collagens with unphysiological orientation and faster synthesis. MRI studies strongly supported that low flow, characterized by low WSS and high blood residence time, was associated with thicker walls and post-contrast enhancement. While significant discrepancies were found among those utilized intraoperative images, they generally supported that thicker walls coexist at regions with prolonged residence time and that thinner regions are mainly exposed to higher pressure with complex WSS patterns. The current body of literature supports a theory of two general hemodynamic-biologic mechanisms for IA development. One, where low flow conditions are associated with thickening and atherosclerotic-like remodeling, and the other where high and impinging flow conditions are related to wall degeneration, thinning, and collagen remodeling.

Imbalanced flow changes of distal arteries: An important factor in process of delayed ipsilateral parenchymal hemorrhage after flow diversion in patients with cerebral aneurysms

BACKGROUND AND OBJECTIVE

Hemodynamic forces may play a role in symptomatic delayed ipsilateral parenchymal hemorrhage (DIPH) of intracranial aneurysm (IA) after flow diverter placement. We aimed to investigate the hemodynamic risk factors in the postsurgical DIPH process.

METHODS

Six patients with internal carotid artery (ICA) aneurysm developed to DIPH and 12 patients without DIPH (1:2 matched controls) after flow diverter were included between January 2015 to January 2019. Postsurgical hemodynamics of distal arteries (terminal ICA, middle cerebral artery (MCA), anterior cerebral artery (ACA)) were investigated using computational fluid dynamics, as well as the hemodynamic alteration between pre- and post-treatment. The DIPH related and unrelated distal arteries (either MCA or ACA) were discriminated and compared. Definition of imbalance index is the difference in increased velocity post-flow diverter between MCA and ACA and was used to evaluate the blood flow distribution of distal arteries.

RESULTS

The mean and maximum flow velocities in the terminal ICA increased significantly after treatment in both groups. In DIPH group, the increase rate of mean velocity in the DIPH-related artery was significantly higher than that in DIPH-unrelated artery after the treatment (20.98 ± 15.38% vs -6.40 ± 7.74%; p = 0.028). Between the DIPH and control group, the baseline characteristics were well matched. However, a higher imbalance index of mean velocity was found in DIPH group (27.38 ± 13.03% vs 10.85 ± 14.12%; p = 0.031).

CONCLUSION

The mean velocity of DIPH related artery increased more, and the imbalance in increased blood flow distribution of distal arteries might play an important role in DIPH after flow diverter of IAs.

Multiple pipeline embolization devices improves aneurysm occlusion without increasing morbidity: A single center experience of 140 cases

INTRODUCTION

Rates of aneurysm occlusion with the pipeline embolization device (PED) has varied widely in the literature from 55.7% to 93.3% at 6 months, which may reflect a difference in technique including sizing and number of devices used.

METHODS

140 cases at our institution were retrospectively reviewed, and aneurysms treated with a single PED vs. multiple were compared.

RESULTS

Complete aneurysm occlusion was achieved in 86.9% at 6 months, 91.8% at 1 year, and 97.6% at longest follow-up. Retreatment with an additional device was required in 7 (5.1%). Major and minor complication rate within 30 days was 1.4% and 5.0%, and at greater than 30 days was 0.8% and 3.1%. Patients treated with multiple PEDs had significantly higher rates of aneurysm occlusion at 6 months (92.9% vs. 75.6%, p = 0.017) and 12 months (98.4% vs. 81.1%, p = 0.014), with no difference in complications. The two groups were similar aside from a higher number of ophthalmic and paraophthalmic aneurysms treated with multiple PEDs (23.4% vs. 6.5%, p = 0.004; and 35.1% vs. 17.4%, p = 0.020), and more posterior communicating artery and recurrent aneurysms treated with a single PED (28.3% vs. 3.2%, p = 0.001; 23.9% vs. 8.5%, p = 0.031). The use of multiple PEDs was found to be an independent predictor of aneurysm occlusion in a multivariate analysis (p = 0.015).

CONCLUSIONS

The use of multiple PEDs for intracranial aneurysms leads to significantly higher occlusion rates without added morbidity. This benefit is particularly appropriate for ophthalmic segment aneurysms, while more distal segments with eloquent perforating branches should be managed with caution.

Management of intracranial aneurysms in France: Place of microsurgery and demography of vascular neurosurgeons

STUDY DESIGN

Observational retrospective survey-based study.

INTRODUCTION

Intracranial aneurysms (IA) can be treated with microsurgery or by endovascular treatments (EVT). EVT have taken an increasingly important part in IA management; the ability of neurosurgical teams to perform such surgery as well as the quality of their training is being questioned. We therefore wanted to assess the proportion of IA treated by microsurgery in France, the demography and caseload of surgeons trained in vascular neurosurgery.

METHODOLOGY

A 60-question survey was sent to the 34 French neurosurgical centers treating IA. Twenty-seven questions dealt with the demography of neurovascular surgeons and caseload. Descriptive data are reported here.

RESULTS

Twenty-seven centers answered, giving us a response rate of 79.4%. A total of 209 neurosurgeons worked in these centers. Forty-six neurosurgeons were designated as referents in vascular neurosurgery, 47% of them were under 45 years old. Among the centers, 96.3% had at least one surgeon that was a referent in neurovascular surgery. A total of 88 surgeons performed IA surgery, but only 11 operated more than 20 IA per year. Two thousand four hundred and thirty seven unruptured IA were treated every year in these centers, 25% of which by microsurgery. A total of 2727 ruptured IA were treated in these centers, of which 15% were treated by microsurgery. The most common indications for microsurgical treatment of IA were: middle cerebral artery aneurysms, wide-neck intracranial aneurysms, and giant intracranial aneurysms, as well as aneurysms associated with a hematoma for the ruptured ones.

CONCLUSION

Demography of vascular neurosurgeons remains favorable, with a referent neurosurgeon in most centers, who, in half of the cases, is a young practitioner. The percentage of microsurgery in the treatment of IA is low, especially for ruptured ones. The most frequently operated types of intracranial aneurysm correspond to good practice recommendations.

Endovascular Treatment of Anterior Circulation Aneurysms With the p64 Flow Modulation Device: Mid- and Long-Term Results in 617 Aneurysms From a Single Center

BACKGROUND

Flow diverters have become an important tool in the treatment of intracranial aneurysms, especially when dealing with difficult-to-treat or complex aneurysms. The p64 is the only fully resheathable and mechanically detachable flow diverter available for clinical use.

OBJECTIVE

To evaluate the safety and effectiveness of p64 for the treatment of intracranial saccular unruptured aneurysms arising from the anterior circulation over a long-term follow-up period.

METHODS

We retrospectively reviewed our prospectively maintained database to identify all patients who underwent treatment for an intracranial saccular (unruptured or beyond the acute hemorrhage phase) aneurysm arising from the anterior circulation with ≥1 p64 between December 2011 and December 2019. Fusiform aneurysms and dissections were excluded. Aneurysms with prior or concomitant saccular treatment (eg, coiling and clipping) were included. Aneurysms with parent vessel implants other than p64 were excluded. Anatomic features, intraprocedural complications, clinical outcome, as well as clinical and angiographic follow-ups were all recorded.

RESULTS

In total, 530 patients (388 females; median age 55.9 yr) with 617 intracranial aneurysms met the inclusion criteria. The average number of devices used per aneurysm was 1.1 (range 1-3). Mean aneurysm dome size was 4.8 mm (range 1-27 mm). Treatment-related morbimortality was 2.4%. Early, mid-term, and long-term angiographic follow-up showed complete or near-complete aneurysm occlusion in 76.8%, 89.7%, and 94.5%, respectively.

CONCLUSION

Treatment of intracranial saccular unruptured aneurysms of the anterior circulation using p64 is a safe and effective treatment option with high rate of occlusion at long-term follow-up and low morbimortality.