Flow Diverter Treatment Research Articles

Abstract TP151: Usefulness of 3D I-Flow Application in Predicting the Outcome of Flow Diverter Stenting for Large or Giant Carotid Aneurysms

Background and Purpose: The flow diverter (FD) has dramatically improved the treatment outcome of large / giant internal carotid artery (IC) aneurysms. However, it is difficult to predict the treatment outcome of FD just after the treatment. 3D iFlow is a novel application of 4D-digital subtraction angiography (4D-DSA) that can evaluate the arrival time of contrast media in 3D images, but its usefulness for neurointervention is unclear. Therefore, the aim of this study was to elucidate the utility of 3D iFlow in predicting the outcome of FD treatment for large / giant IC aneurysms. Methods: A total of 8 cases of large / giant aneurysms at IC cavernous portion treated with FD and were enrolled in this study. 3D iFlow images before and after placement of FD were acquired in all cases. Treatment outcome was evaluated by O’Kelly-Marotta(OKM) Grading Scale with DSA 6 months after treatment. The regions of interests (ROI) were set in IC bifurcation and petrous segment with 3D iFlow application, and the 3D iFlow transit time was measured by comparing the peak contrast intensities in 2 ROIs. We investigated the rate of changes in 3D iFlow transit time before and after the placement of FD. Results: FD was deployed successfully in all cases without coils. The number of OKM grade B, C and D with DSA 6 months after treatment were 2, 3 and 3 cases, respectively. The rate of changes in 3D iFlow transit time was significantly shorter in OKM grade D cases compared with grade B and C (52.5% vs 84.7%, p=0.03). Conclusion: 3D iFlow application may be effective to predict the treatment outcome of FD.

Evaluation of the Significance of Persistent Remnant Filling and Enlargement After Flow Diversion for Intracranial Aneurysms

BackgroundThis study aimed to evaluate the clinical course after flow diversion treatment with a focus on aneurysms with remnant sac filling, by analyzing angiographic outcomes, aneurysm volume, and clinical events. MethodsWe retrospectively reviewed the medical records of 61 patients who underwent flow diversion for intracranial aneurysms between July 2014 and June 2021. ResultsThe majority of aneurysms (52.5%) were located in the internal carotid artery, with a median diameter of 16.6 mm and neck size of 9.3 mm. Remnant filling was observed in 17 aneurysms (27.9%) more than 18 months after flow diversion, 10 (16.4%) of these aneurysms underwent enlargement, which occurred only in cases with subtotal filling or entry remnant states. Eleven patients experienced major adverse events, and three exhibited unfavorable functional outcomes. The incidence of major adverse events and unfavorable functional outcomes was significantly higher in the aneurysm enlargement group than that in the no-filling or stable remnant filling groups (p<0.001). Aneurysmal diameter and the presence of incorporated branches were independent predictors of aneurysm enlargement, while the presence of incorporated branches was the only independent predictor of persistent remnant filling. ConclusionsAneurysm enlargement after flow diversion is not uncommon, particularly when the aneurysm is large, has incorporated vessels, or does not undergo occlusion within 12 months, often culminating in major adverse events and unfavorable functional outcomes. In addition to investigating angiographic results, it is necessary to evaluate the changes in aneurysm size and clinical events when assessing the efficacy of flow diversion.

Endovascular Treatments for Aneurysms Involving a Major Branch.

Remarkable advances have been made in the endovascular treatment of intracranial cerebral aneurysms. These advances include various adjunctive techniques, increased indications for endovascular treatment, and improved treatment results. Furthermore, the number of cerebral aneurysm treatments using flow diverters (FDs) is expected to increase. However, the reported long-term rate of branch artery occlusion after FD treatment has been reported is 15.8%. Moreover, the complete aneurysm obliteration rate is low if normal branches arise from an aneurysm neck or dome. Flow diverter placement for ophthalmic artery, posterior communicating artery, and anterior choroidal artery aneurysms is often difficult because these normal branches often arise from the aneurysm neck or dome. Therefore, in many cases, coil embolization, which can occlude the aneurysm while preserving branch vessels, should be selected. Although not yet established, various adjunctive techniques and other endovascular treatments that can be performed safely have been reported. Treatment must be planned after understanding the advantages and disadvantages of each treatment method.

A case of flow diverter treatment by transradial approach of a left internal carotid artery aneurysm with an aberrant right subclavian artery

A case of flow diverter treatment by transradial approach of a left internal carotid artery aneurysm with an aberrant right subclavian artery

Flow diverter treatment for dissecting aneurysm causing cavernous sinus syndrome

A sinus cavernosus szindróma egyoldalú ophthalmoplegia, autonóm diszfunkció és a nervus trigeminus ophthalmicus vagy maxillaris ága szenzoros kiesésének kombinációja. Fejsérülést követően sinus cavernosus szindróma jelentkezése esetén mindenképpen gondoljunk a dissectiós eredetű aneurysma lehetőségére. Vérzett aneurysmák mellett a ’silent’ intracranialis aneurysmákat is kezelnünk kell, ha kompressziós tüneteket okoznak. Esetismertetésünkben egy 23 éves nőbeteg sikeres kezelését mutatjuk be, aki esés során eszméletét vesztette, majd azonnal jobb oldali ptosis, ophthalmoplegia és arc területi érzéskiesés jelentkezett. Az angiográfia a jobb arteria carotis interna sinus cavernosus szakaszán dissectiós aneurysmát igazolt, melyet a sérülést követő 6. napon áramlásmódosító sztenttel kezeltünk. A beavatkozás szövődménymentesen zajlott, gyors és teljes radiológiai és klinikai gyógyulást eredményezett. Esetismertetésünk is megerősíti azt a metaanalíziseken alapuló tényt, hogy az arteria carotis interna sinus cavernosus szakaszán jelentkező dissectiós aneurysma áramlásmódosító sztenttel biztonságosan és sikeresen kezelhető. Ha a kezelés minél korábban elvégezhető, akkor a sinus cavernosus szindróma minden tünete rendeződik, az azonos oldali ophthalmoplegia és az arc érzéskiesése néhány napon belül tökéletesen gyógyulhat. Orv Hetil. 2023; 164(52): 2074–2078.

Correlation of Flow Diverter Malapposition at the Aneurysm Neck with Incomplete Aneurysm Occlusion in Patients with Small Intracranial Aneurysms: A Single-Center Experience.

Flow diversion treatment repairs aneurysms by altering the hemodynamics of the aneurysmal sac and providing a scaffold for endothelial cell adhesion. The purpose of this study was to investigate the correlation of flow diverter (FD) malapposition at the aneurysm neck with incomplete occlusion of small intracranial aneurysms (IAs) and investigate other factors that are possibly related to incomplete occlusion. From January 2019 to June 2022, the clinical and imaging data for 153 patients (175 aneurysms) with unruptured small IAs treated with flow diversion were retrospectively analyzed. FD apposition at the aneurysm neck was evaluated by high-resolution conebeam CT (HR-CBCT), and the complete occlusion rate for aneurysms was judged according to the latest follow-up conventional angiography findings (≥6 months). Multivariate logistic regression analysis was used to determine factors associated with incomplete aneurysm occlusion. In total, 159 FDs were implanted in 153 patients. HR-CBCT performed after the deployment revealed FD malapposition at the aneurysm neck in 18 cases. According to the latest follow-up angiograms (average: 9.47 ± 3.35 months), the complete aneurysm occlusion rate was 66.9%. The complete occlusion rates for incomplete and complete stent apposition at the neck were 38.9% (7/18) and 70.1% (110/157), respectively. The results of regression analysis showed that an aneurysm sac with branch vessels (OR, 2.937; P = .018), incomplete stent apposition at the aneurysm neck (OR, 3.561; P = .023), and a large aneurysm diameter (OR, 1.533; P = .028) were positive predictors of incomplete aneurysm occlusion. An aneurysm sac with branch vessels, a large aneurysm diameter, and malapposition at the aneurysm neck significantly affect aneurysm repair after FD stent-only treatment for small IAs.

Predictors of aneurysm shrinkage after flow diversion treatment for internal carotid artery aneurysms: quantitative volume analysis with MRI.

Although aneurysm shrinkage often occurs after flow diversion treatment for intracranial aneurysms, no reports have addressed the factors associated with aneurysm shrinkage. This retrospective single-center study was performed to examine patients with unruptured internal carotid artery aneurysms who were treated using flow diversion and followed up by imaging for at least 12 months. The study outcome was aneurysm shrinkage (volume reduction of ≥10%) 12 months after treatment. Aneurysm volume was quantitatively assessed using the MRIcroGL software. Patient and aneurysm characteristics were statistically analyzed. This study involved 81 patients with 88 aneurysms. At the 6 months, 12 months, and last follow-ups, the proportion of aneurysms that had shrunk was 50, 64, and 65%, respectively. No adjunctive coiling (odds ratio, 56.7; 95% confidence interval, 7.03-457.21; p < 0.001) and aneurysm occlusion (odds ratio, 90.7; 95% confidence interval, 8.32-988.66; p < 0.001) were significantly associated with aneurysm shrinkage. In patients treated by flow diversion with adjunctive coiling, only the volume embolization rate was a factor significantly associated with aneurysm shrinkage (p < 0.001). Its cutoff value was 15.5% according to the receiver operating characteristic curve analysis (area under the curve, 0.87; sensitivity, 0.87; specificity, 0.83). The rate of aneurysm shrinkage after flow diversion increased during the first 12 months after treatment, but not thereafter. No adjunctive coiling and aneurysm occlusion were predictors of aneurysm shrinkage, respectively. If adjunctive coiling is required, a volume embolization rate of ≤15.5% may be suggested for aneurysm regression.

Braid stability after flow diverter treatment of intracranial aneurysms: a systematic review and meta-analysis.

The aim of this study was to evaluate the overall rates of braid changes associated with flow diverter (FD) treatment for intracranial aneurysms (IAs). Additionally, we sought to provide an overview of the currently reported definitions related to these complications. A systematic search was conducted from the inception of relevant literature up to April 2023, encompassing six databases. The included studies focused on patients with IAs treated with FDs. We considered four main outcome measures as FD braid changes: (1) fish-mouthing, (2) device braid narrowing, (3) device braid collapsing, and (4) device braid deformation. The data from these studies were pooled using a random-effects model. A total of 48 studies involving 3572 patients were included in the analysis. Among them, 14 studies (39%) provided definitions for fish-mouthing. However, none of the included studies offered specific definitions for device braid narrowing, collapsing, or deformation, despite reporting rates for these complications in six, five, and three studies, respectively. The pooled rates for braid changes were as follows: 3% (95% CI 2% to 4%, I2=27%) for fish-mouthing, 7% (95% CI 2% to 20%, I2=85%) for narrowing, 1% (95% CI 0% to 3%, I2=0%) for collapsing, and 1% (95% CI 1% to 4%, I2=0%) for deformation. The findings of this study suggest that FD treatment for IAs generally exhibits low rates of fish-mouthing, device braid narrowing, collapsing, and deformation. However, the lack of standardized definitions hinders the ability to compare device outcomes objectively, emphasizing the need for uniform definitions for FD braid changes in future prospective studies on FD.

Flow diversion for unruptured fusiform aneurysms of the proximal middle cerebral artery.

Managing fusiform aneurysms of the proximal (M1) segment of the middle cerebral artery (MCA) is challenging due to difficulties in both surgical and endovascular treatment. In this study, we present our experience using flow diverter stents for managing unruptured M1 segment fusiform aneurysms. We conducted a retrospective review of the database of our institution to identify all patients who underwent flow diversion treatment for unruptured M1 segment fusiform aneurysms. We collected data on patient demographics, aneurysm characteristics, complications, angiographic follow-up results, and clinical outcomes. A total of 10 patients (five male and five female patients) with 10 unruptured M1 segment fusiform aneurysms were included in the study. The average age of the patients was 48 years (range: 16-64 years); five patients had aneurysms smaller than 10 mm, four had aneurysms measuring between 10 and 25 mm, and one patient had an aneurysm larger than 25 mm. The successful deployment of flow-diverting stents was achieved in all cases. Procedure-related morbidity was observed in 10% of patients, but there were no deaths. All patients showed good outcomes (modified Rankin Scale score of 0-1); eight out of 10 patients had available follow-up angiography results with a mean follow-up period of 11.6 months (range: 6-24 months). Complete occlusion occurred in six out of eight reviewed cases (75%). Our preliminary findings suggest that using flow diversion for treating unruptured fusiform aneurysms in the proximal MCA is feasible and safe, with a satisfactory rate of complete occlusion. However, further studies involving larger case series are needed to validate the durability and efficacy of this treatment approach.

Safety of dual antiplatelet therapy using aspirin and low-dose Prasugrel with platelet reactivity testing in flow diverter treatment of intracranial aneurysms.

Dual antiplatelet therapy (DAPT) is standard care for intracranial stenting to prevent thrombotic complications. Clopidogrel resistance has resulted in patients receiving newer P2Y12 inhibitors like Prasugrel, which may reduce thrombotic complications but could increase haemorrhagic complications. This study, utilising platelet reactivity testing, compared thrombotic and haemorrhagic complications associated with Clopidogrel or 20 mg Prasugrel loading in patients treated with flow diverters (FD) for intracranial aneurysms. We retrospectively analysed prospectively collected data from 225 consecutive FD procedures. All patients received aspirin. 147 cases received Clopidogrel and 82 received Prasugrel. All patients had VerifyNow testing before the procedure. P2Y12 non-responders were significantly more likely to have thrombotic complications than responders and hyper-responders (7% vs. 2%, p = 0.01). Low-dose Prasugrel resulted in a significantly lower rate of non-responders when compared with Clopidogrel (7% vs. 25%, p < 0.01). We found no statistically significant difference in rates of haemorrhage between the Clopidogrel and Prasugrel groups (2.4% vs. 3.9%, p = 0.47). There were 12 complications (≤7 days) in the Clopidogrel group versus 6 in the Prasugrel group (9% vs. 7.8%, respectively, p = 0.91) and a non-significant reduction in thrombotic complications in the Prasugrel group (5.2% vs. 3.9%, p = 0.88). No significant difference was shown in long-term complications between the groups (p = 0.33). These results support the use of platelet reactivity testing and the safety of low-dose Prasugrel for FD treatment of intracranial aneurysms.

AneuGuide™ software-assisted vs. manual measurements in sizing for pipeline embolization device: An agreement study

Sizing of flow diverters (FDs) is a challenging task in the treatment of intracranial aneurysms due to their foreshortening behavior. The purpose of this study is to evaluate the difference between the sizing results from the AneuGuide™ software and from conventional 2D measurement. Ninety-eight consecutive patients undergoing pipeline embolization device (PED) treatment between October 2018 and April 2023 in the First Medical Center of Chinese PLA General Hospital (Beijing, China) were retrospectively analyzed. For all cases, the optimal PED dimensions were both manually determined through 2D measurements on pre-treatment 3D-DSA and computed by AneuGuide™ software. The inter-rater reliability between the two sets of sizing results for each methodology was analyzed using intraclass correlation coefficient (ICC). The degree of agreement between manual sizing and software sizing were analyzed with the Bland-Altman plot and Pearson's test. Differences between two methodologies were analyzed with Wilcoxon signed rank test. Statistical significance was defined as p < 0.05. There was better inter-rater reliability between AneuGuide™ measurements both for diameter (ICC 0.92, 95%CI 0.88–0.95) and length (ICC 0.93, 95%CI 0.89–0.96). Bland-Altman plots showed a good agreement for diameter selection between two methodologies. However, the median length proposed by software group was significantly shorter (16 mm versus 20 mm, p < 0.001). No difference was found for median diameter (4.25 mm versus 4.25 mm). We demonstrated that the AneuGuide™ software provides highly reliable results of PED sizing compared with manual measurement, with a shorter stent length. AneuGuide™ may aid neurointerventionalists in selecting optimal dimensions for FD treatment.

Abstract 138: Use of a 046” Intermediate Guide Catheter for Mini‐Triaxial Access in Flow Diversion: Multi‐institution Experience

Introduction The latest FDA‐approved intermediate guide catheter, Vecta46, allows for a unique, mini‐triaxial access platform. The size of this catheter allows for 058” guide compatibility, intraluminal accommodation of an 027” microcatheter for flow diverter delivery, and angiographic procedural injections in an 070” guide catheter. Methods We retrospectively identified and analyzed patients who underwent Surpass Evolve flow diversion treatment utilizing the Vecta46 across the senior authors’ institutions. Results The use of the Vecta46 was identified for treatment of 9 aneurysms treated with the Surpass Evolve Flow Diverter (March to April 2023), in patient’s aged 61±3.5 years (range 40‐74 years) with 89% (n=8) female. Aneurysm average size of 4.3±0.47mm, aneurysms originating along the internal carotid artery (n=6) and MCA branches (n=4). Preoperative PRU measured 92 ± 21. Radial access was utilized in 2 cases. Mean Surpass Evolve utilized was 4.4±0.17mm (diameter) by 15.7±0.88mm (length). An 071” guide catheter (Armadillo, Q’Appel Medical) was used in 8 cases. Vecta46 was safely navigated to the supraclinoid ICA segment in all cases. Average fluoroscopy time was 24±3.1 minutes, radiation exposure was 756±259mGy, and verapamil was used in all cases. Technical success was achieved in all cases with adequate vessel wall apposition verified. There were no hemorrhagic complications nor parent vessel wall dissection or vasospasm in the region of the Vecta46 catheter on final control angiography in all 9 cases. Conclusion The new low‐profile Vecta46 intermediate catheter can be safely and effectively utilized in a 6‐French mini‐triaxial system for flow diverter delivery without compromising injection quality, support, or trackability.

Flow diverter surface modifications for aneurysm treatment: A review of the mechanisms and data behind existing technologies.

Flow diversion (FD) has become a mainstay treatment for large wide-necked aneurysms. Despite excellent safety and efficacy, the risk of thromboembolic complications necessitates the use of dual antiplatelet therapy (DAPT). The use of DAPT makes hemorrhagic complications of stenting carry high morbidity and mortality. Additionally, DAPT usage carries a risk of "nuisance" complications that do not directly impact intracranial circulation but need to be managed nonetheless. To circumvent this issue, the most recent generation of flow diverters have undergone surface modification with various compounds to confer blood compatibility to limit clotting and thrombosis. While these newer generation flow diverters are marketed to enhance ease of deployment, the goal is to eventually facilitate single antiplatelet use with flow diverter treatment. This generation of FDs have potential to expand indications beyond unruptured wide-necked aneurysms to include ruptured intracranial aneurysms without the necessity of DAPT. Currently, no comprehensive review details the molecular mechanisms and pre-clinical and clinical data on these modifications. We seek to fill this gap in the literature by consolidating information on the coating technology for four major FDs currently in clinical use-PipelineTM Flex and Vantage Shield TechnologyTM, FREDTMX, p48/64 hydrophilic coating, and Acandis Dervio® 2heal-to serve as a reference guide in neurointerventional aneurysm treatment. Although the Balt silkTM was one of the first FDs, it is uncoated, thus we will not cover this device in our review. A literature review was performed to obtain information on each coating technology for the major flow diverters currently on the market using international databases (PUBMED, Embase, Medline, Google Scholar). The search criteria used the keywords for each coating technology of interest "phosphorylcholine," "poly 2-methoxyethyl acrylate," "hydrophilic polymer coating," and "fibrin-heparin" Keywords related to the device names "Pipeline Shield," "Pipeline Shield with Flex Technology," "FRED," "FREDX," "p64," "p64-HPC," "Derivo 2heal" were also used. Studies that detailed the mechanism of action of the coating, any pre-clinical studies with surface-modified intravascular devices, and any clinical retrospective series, prospective series, or randomized clinical trials with surface-modified devices for aneurysm treatment were included.

Inflow Angle and Height-Width Ratio are Predictors of Incomplete Occlusion at One and Two Years After Flow Diverter Treatment for Small- and Medium-Sized Internal Carotid Artery Aneurysms

We investigated the association between the inflow angle of aneurysms and their occlusion status at 1 and 2years after flow diverter (FD) treatment. We retrospectively analyzed 42 consecutive patients from a single center with 43 untreated, unruptured internal carotid artery (ICA) proximal to communicating segment, saccular aneurysms sized <12mm. At 1year posttreatment, the complete occlusion (CO) rate was 58.1%. On univariate analyses, the proportion of inflow angle >90° was significantly lower in the CO group than in the incomplete occlusion group (20.0% VS. 83.3%; P < 0.001). The CO incidence decreased with a height-width (H/W) ratio of <1.2 (P= 0.059). On multivariate analysis, an H/W ratio of <1.2 (odds ratio [OR], 0.076; P= 0.027) and an inflow angle of >90° (OR, 0.020; P= 0.0011) significantly influenced CO at 1year post FD. At 2years posttreatment, the CO rate was 76.3% (29/38 cases with available follow-up data). On univariate analyses, in the CO group compared to the incomplete occlusion group, the proportion of H/W ratio <1.2 was significantly lower (P= 0.005) and the proportion of inflow angle >90° was significantly lower (P= 0.021); aneurysm dome size tended to be larger (8.5mm vs. 7.1mm; P= 0.080). On multivariate analysis, an H/W ratio <1.2 (OR, 0.042; P= 0.015) and an inflow angle >90° (OR: 0.088; P= 0.031) significantly influenced CO at 2years post FD. The inflow angle of >90° and H/W ratio <1.2 may significantly influence the CO rate in small- or medium-sized internal carotid artery aneurysms 1 and 2 years post FD.

Partially thrombosed giant basilar artery aneurysm with attenuated contrast enhancement of the intraluminal thrombus on vessel wall MRI after flow diversion treatment: illustrative case.

The effect of vessel wall magnetic resonance imaging (VW-MRI) enhancement in partially thrombosed aneurysms has previously indicated aneurysmal instability and a rupture risk. However, whether the contrast effect of the wall changes before or after flow diversion treatment is still under investigation. The authors report a case of a partially thrombosed basilar artery aneurysm that increased in size over a short period, worsened brainstem compression symptoms, and was treated with a flow diverter stent with good results. In this case, VW-MRI after surgery showed a reduced contrast effect on the intraluminal thrombus within the aneurysm. The aneurysm thrombosed and markedly regressed over the next 5 months, with remarkable improvement in the brainstem compression symptoms. This finding on VW-MRI may indicate an attenuation of neovascularization in the thrombus wall and be a sign of aneurysm stabilization.

Does the clopidogrel CYP2C19 genotype assay predict postprocedure stenosis in cerebral aneurysms treated with a flow diverter?

Flow diverters have emerged as a popular modality for treating cerebral aneurysms but require dual antiplatelet therapy (DAPT) after placement. Clopidogrel is a common choice but is a prodrug that some patients may not convert into an active metabolite. The CYP2C19 genotype assay is used to predict activation speed; however, limited data exist showcasing whether this genotype accurately predicts postprocedure complications after flow diversion treatment of cerebral aneurysms. Therefore, the authors sought to characterize whether CYP2C19 genotype correlated with the development of postprocedure intimal hyperplasia (stenosis) after flow diverter placement. Medical records were reviewed for patients who underwent flow diverter treatment of cerebral aneurysm at a single academic institution between January 1, 2012, and May 31, 2020. Patient demographics and comorbidities were reviewed alongside CYP2C19 genotype assay, DAPT regimen, and postprocedure angiogram data. Stenosis was defined based on review of angiogram data by two independent physicians. In this review of 120 unique cerebral aneurysms, 102 received DAPT with clopidogrel and 18 received DAPT with an alternative agent. Stenosis was present on 3-month follow-up angiogram for 35/102 (34.3%) aneurysms receiving DAPT with clopidogrel and in 11/18 (61.1%) aneurysms receiving an alternative DAPT regimen (p = 0.031). The CYP2C19 genotype did not correlate with postprocedure stenosis (p = 0.35). Clopidogrel was a significantly more effective DAPT agent for preventing stenosis when compared to nonclopidogrel DAPT regimens. The clopidogrel CYP2C19 genotype did not predict postprocedure stenosis in this cohort of 120 cerebral aneurysms treated with a flow diverter.

Visual Morbidity in Patients With Ophthalmic Segment Aneurysms Treated With Flow Diverters: A Dual-Center Experience.

Flow diverter (FD) treatment for aneurysms of the ophthalmic segment of the internal carotid artery (ICA) may raise concerns about visual morbidity related to coverage of the ophthalmic artery by the device. Our objective was to evaluate clinical and angiographic outcomes associated with FD treatment of these aneurysms, with particular emphasis on visual morbidity. We performed a retrospective analysis of the endovascular databases at 2 US centers to identify consecutive patients with aneurysms along the ophthalmic segment of the ICA that were treated with FDs between January 2010 and December 2022. Baseline demographics, aneurysm characteristics, and periprocedural and postprocedural data, including the occurrence of visual complications, were collected. One hundred and thirteen patients with 113 aneurysms were identified for inclusion in this study. The mean age of the patients was 59.5 ± 12.4 years, and 103 (91.2%) were women. The ophthalmic artery origin was involved in 40 (35.4%) aneurysms, consisting of a neck origin in 33 (29.2%) and a dome origin in 7 (6.2%). New transient visual morbidity during the hospital stay included impaired visual acuity or blurriness in 1 (0.9%) patient, diplopia in 1 (0.9%), and floaters in 1 (0.9%). New transient visual morbidity during follow-up included impaired visual acuity or blurriness in 5 patients (4.4%), diplopia in 3 (2.7%), ipsilateral visual field defect in 1 (0.9%), and floaters in 6 (5.3%). Permanent visual morbidity occurred in 1 patient (0.9%). Among the 101 patients who had angiographic follow-up, the Raymond-Roy occlusion classifications were I (complete aneurysm occlusion) in 85 (84.2%), II (residual neck) in 11 (10.9%), and III (residual aneurysm) in 5 (4.9%). In our experience, flow diversion for ICA ophthalmic segment aneurysms resulted in low rates of visual morbidity, which was mostly transient in occurrence.

Utility of follow-up ultra-high-resolution CT angiography with model-based iterative reconstruction after flow diverter treatment for cerebral aneurysms.

Follow-up examinations after flow diverter (FD) treatment for cerebral aneurysms typically involve magnetic resonance imaging (MRI) or digital subtraction angiography (DSA). However, MRI is prone to vascular defects due to metal artifacts from FD, and DSA carries a risk of ischemic complications. In the context of computed tomography angiography (CTA), this study compares the efficacy of ultra-high-resolution CT (UHRCT) and novel reconstruction techniques, such as model-based iterative reconstruction (MBIR), against conventional methods such as filtered back projection (FBP) and hybrid iterative reconstruction (IR), to determine if they are a viable alternative to DSA in clinical settings. A phantom study was conducted with the full-width half-maximum considered as the FD thickness. This study compared three reconstruction methods: MBIR, FBP, and hybrid IR. A clinical study was also conducted with 21 patients who underwent follow-up CTA after FD treatment. The FD's visibility was assessed using a 4-point scale in FBP, hybrid IR, and MBIR compared to cone-beam CT (CBCT) with angiographic systems. In the phantom study, FBP, hybrid IR, and MBIR visualized thinner FD thicknesses and improved detail rendering in that order. MBIR proved to be significantly superior in both the phantom and clinical study. UHRCT with MBIR is highly effective for follow-up evaluations after FD treatment and may become the first-choice modality in the future.

Factors influencing early obliteration during flow diverter treatment of cerebral aneurysms: Establishment of an early obliteration inhibition score.

This retrospective study aimed to investigate factors associated with inhibition of early aneurysm obliteration after flow diverter (FD) treatment. We also created the early obliteration inhibition (EOI) score for pre-operative evaluation. We examined 110 cerebral aneurysms in 104 patients who underwent FD treatment. The following parameters were investigated: age, sex, symptoms, aneurysm location and type, maximum aneurysm diameter, parent vessel diameter, neck diameter, and dome-neck ratio. We also noted aneurysm location relative to the curvature of the parent artery and any branches arising from the aneurysm dome. Procedural factors such as FD diameter and length, number of FDs placed, type of FD, and use of adjunctive coiling were also investigated. Aneurysm obliteration was evaluated using digital subtraction angiography 3 months after the procedure. Adequate obliteration was defined as grade C or D on the O'Kelly-Marotta scale. The following factors inhibited early obliteration: 1) extradural location, 2) saccular aneurysm, 3) aneurysm neck located at the outer convexity of the parent artery, and 4) arterial branch arising from the aneurysm dome. Odds ratios were used to create an EOI score. Receiver operating characteristic curve analysis showed that the optimal cut-off EOI score for adequate obliteration was 1.5 (area under the curve, 0.81; 95% confidence interval, 0.73-0.9; sensitivity, 0.9; specificity, 0.57). The EOI score, which is based on factors that inhibit early obliteration, may predict early treatment outcomes of FD placement.

Impact of branch arteries on efficacy of endoluminal flow diverters: Insights from posterior communicating artery aneurysms.

Flow diverter treatment may inevitably require jailing of the branch vessels. While the patency of covered branch arteries and associated safety risks have been a topic of substantial interest, the question of whether the characteristics of branch vessels affect flow diversion's efficacy remains unanswered. In this study, we aimed to assess the impact of branch arteries on the efficacy of endoluminal flow diverters, specifically focusing on posterior communicating artery (Pcomm) aneurysms. Following PRISMA guidelines, we systematically searched the MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane databases with predefined keywords. Studies providing data for flow diversion outcomes in Pcomm aneurysms were included. Outcomes of interest included complete and adequate aneurysm obliteration, ischemic and hemorrhagic complications, and Pcomm occlusion in the follow-up period. A random or fixed effects model was used to calculate the odds ratios (ORs) and pooled event rates with their corresponding confidence intervals (CI). The overall complete and adequate aneurysm occlusion rates were 72.25% (95% CI: 64.46-78.88%) and 88.37% (95% CI: 84.33-92.6), respectively. Fetal-type Pcomm aneurysms had significantly lower complete aneurysm occlusion rates than the nonfetal-type Pcomm aneurysms (OR: 0.12, 95% CI: 0.05-0.29). Overall ischemic and hemorrhagic complication rates were 2.62% (95% CI = 0.71-5.32) and 0.71% (95% CI: 0-2.24), respectively. There were no significant associations between Pcomm morphology and complications (OR: 3.61, 95% CI = 0.42-31.06 for ischemic complications and OR: 2.31, 95% CI = 0.36-14.6 for hemorrhage). Overall Pcomm occlusion rate was 32.04% (95% CI = 19.96-47.13), and the Pcomm patency was significantly lower in nonfetal-type Pcomm aneurysms (OR: 0.10, 95% CI = 0.02-0.44). Our meta-analysis suggests that flow diversion is a safe treatment option for Pcomm aneurysms, regardless of fetal-type Pcomm morphology. However, on the other hand, our findings indicate that Pcomm anatomy or the presence of jailed large branches can affect the efficacy of flow diverter treatment.