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INTRODUCTION: Pediatric intracranial aneurysms (IAs) are rare and have distinct clinical profiles compared to adult IAs. They differ in location, size, morphology, presentation, and treatment strategies. We present our experience with pediatric IAs over an 18-year period using surgical and endovascular treatments and review the literature to identify commonalities in epidemiology, treatment, and outcomes. METHODS: We identified all patients

Osteogenesis imperfecta (OI) predisposes individuals to easy bone fracture, vessel fragility, and platelet dysfunction. We report the first known case of neurointerventional treatment with flow diversion of intracranial aneurysms in a patient with OI. A 62 year-old female with known OI Type I, history of >40 lifetime bone fractures and hypertension, underwent workup for transient ischemic attacks revealing a 4-mm right A1 segment aneurysm in 2016. Perioperative dual antiplatelet therapy was aspirin 81 mg and clopidogrel 37.5 mg daily. Tri-axial access was utilized to deploy a 3.5 × 16-mm Pipeline Flex device without complication. Two-month follow-up revealed Raymond I (OKelly Marotta I) obliteration of the aneurysm. Five-year follow-up revealed a de novo left-sided 3-mm A1-A2 junction aneurysm. A 4 × 12-mm Surpass Evolve was placed without complication. Six-month follow-up revealed Raymond I (OKelly Marotta I) obliteration of the second aneurysm. The patient remained asymptomatic at all follow-up visits.

ABSTRACT The mechanisms leading to aneurysm occlusion after treatment with flow‐diverting devices are not fully understood. Flow modification induces thrombus formation within the aneurysm cavity, but fibrin can simultaneously accumulate and cover the device scaffold, leading to further flow modification. However, the interplay and relative importance of these processes are not clearly understood. A computational model of fibrin accumulation and flow modification after flow diversion treatment of cerebral aneurysms has been developed under the guidance of in vitro experiments and observations. The model is based on the loose coupling of flow and transport‐reaction equations that are solved separately by independent codes. Interaction or reactive terms account for thrombin production from prothrombin stimulated by thrombogenic metallic wires and inhibition by antithrombin as well as fibrin production from fibrinogen stimulated by thrombin and flow shear stress, and fibrin adhesion to device wires and already attached fibrin. The computational model was demonstrated and tested on idealized vessel and aneurysm geometries. The model was able to reproduce the salient features of fibrin accumulation after the deployment of flow‐diverting devices in idealized in vitro models of cerebral aneurysms. Namely, fibrin production in regions of high shear stress, initial accumulation at the inflow zone, and progressive occlusion of the device and corresponding flow attenuation. The computational model linking flow dynamics to fibrin production, transport, and adhesion can be used to investigate and better understand the effects that lead to fibrin accumulation and the resulting aneurysm inflow reduction and intra‐aneurysmal flow modulation. [ABSTRACT FROM AUTHOR]

Factors impacting the rate of aneurysm occlusion after flow diversion (FD) have been well described in the literature. In this article, we sought to evaluate those variables to develop and validate a scoring system predicting aneurysm incomplete occlusion after FD. Retrospective review of patients with intracranial aneurysms treated with FD at a single institution between March 2013 and March 2023. Multivariable logistic regression model was developed using factors associated with aneurysm incomplete occlusion. The ABC scoring system consisted of: A ge (<60 years old: 0, 60–69 years: 1, 70–79: 2, and ≥80: 3), B ranch coming out of the aneurysm dome/neck (yes: 2, no: 0), and C igarette smoking history (never smoker: 1, current or past smoker: 0). The scoring system performance was evaluated with receiver operating characteristic curve and calculating the area under the curve. A total of 449 patients with 563 aneurysms treated in 482 procedures were evaluated. Most cases were females (81.7%) with a median age of 59 years old. At a median follow-up of 13.2 months, 84.0% of aneurysms were completely or near-complete occluded. The scoring system had an area under the curve of 0.71. A value ≥ 2, reached a sensitivity of 74.4%, a specificity of 60.9%, a likelihood ratio+ of 1.90, and proved to be reliable in predicting the risk of incomplete occlusion (odds ratio = 4.53; 95% confidence interval: 2.73–7.54; P < 0.001). The proposed ABC scoring system can be used to evaluate the risk of aneurysm incomplete occlusion after treatment with FD, identifying patients who would benefit from adjunctive coiling or alternative treatment modalities. [ABSTRACT FROM AUTHOR]

Endovascular options for the treatment of basilar apex aneurysms (BAAs) are heterogeneous, and evidence is limited to retrospective cohorts and case series. We seek to evaluate the efficacy and complications associated with various endovascular treatment methods of BAAs. Systematic review of PubMed, Embase, and Web of Science adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Retrospective and prospective studies evaluating endovascular treatment of BAAs between January 2010 and July 2024 were included. Relevant information including occlusion rates, aneurysm recurrence, retreatment rates, and complications were subjected to meta-analysis. Fifteen studies with 1049 BAAs were included. The median aneurysm diameter was 8.5 mm (range, 4.6–19.75), with a median follow-up of 33.7 months (range, 6.0–117.6). Residual aneurysm filling occurred in 24% after primary coiling (95% CI = 0.16–0.32), 25% after single stent-assisted coiling (s-SAC; 95% CI = 0.04–0.46), 25% after Y-stents (95% CI = 0.12–0.37), and 23% after flow diverter stent (FDS; 95% CI = 0.11–0.35). Recurrence rates were high for primary coiling (27%, 95% CI = 0.18–0.36) and s-SAC (19%, 95% CI = 0.13–0.26), but significantly lower for Y-stents (9%, 95% CI = 0.03–0.15) and FDS (4%, 95% CI = −0.04–0.11). Retreatment rates were 19% for primary coiling (95% CI = 0.12–0.26), 17% for s-SAC (95% CI = 0.07–0.27), 5% for Y-stents (95% CI = −0.03–0.12), and 13% for FDS (95% CI = −0.01–0.27). Meta-regression indicated larger aneurysms had higher complication rates (P = 0.02). Thromboembolic events were most frequent with FDS and Y-stents(12%). Occlusion rates were similar across treatments, but recurrence rates were significantly lower after Y-stents and FDS compared to primary coiling, although they carried a higher number of thromboembolic complications. [ABSTRACT FROM AUTHOR]

Introduction: The Derivo 2 Heal Embolization Device (D2HED) is a novel flow diverter (FD) providing a fibrin-/heparin-based surface coating aiming at lower thrombogenicity. We evaluate periprocedural aspects and preliminary aneurysm occlusion efficacy for intracranial aneurysm treatment. Methods: Thirty-four D2HEDs deployments (34 aneurysms, 32 patients) between 04/2021 and 10/2023 were analyzed. All patients were under dual antiplatelet therapy (dAPT). Periprocedural details, adverse events, and follow-up (FU) imaging were reviewed by consultant-level neuroradiologists. Complication rates and aneurysm occlusion efficacy are compared with performance data of other FDs based on literature research. Results: Each intervention succeeded in the deployment of one D2HED. Significant and/or increased intraaneurysmal contrast stagnation immediately after D2HED deployment was seen in 73.5% of cases according to O'Kelly-Marotta (OKM) grading scale. Clinically relevant early adverse events occurred in three patients: Among them two cases with fusiform aneurysms in the posterior circulation (ischemic events, early in-stent-thrombosis) and one patient (ischemic event) out of the majority of 31 treated internal carotid artery aneurysms (3,2%). Regarding mid-term FU (> 165 days), one aneurysm did not show progressive occlusion presumably caused by a prominent A1 segment arising from the terminal ICA aneurysm itself. Apart from that, mid-term complete / partial occlusion rates of 80% / 20% could be demonstrated. Conclusion: Our case series - although suffering from restricted sample size - suggests a potential effectiveness of D2HED in managing intracranial aneurysms. Further studies with larger samples are warranted to quantify long-term occlusion efficacy and the impact of antithrombogenic surface coating on the necessary (d)APT. [ABSTRACT FROM AUTHOR]

Hydrologic stress is increasing in Fremont cottonwood (Populus fremontii) forests across the southwestern United States because of increased temperature and streamflow diversion. The spatial variability of this stress is large yet poorly understood. Along the Yampa and Green Rivers in Colorado and Utah, vapour pressure deficit and flow diversions increase downstream. To investigate effects of this gradient on cottonwoods, we measured the percent live canopy and height of randomly selected trees at three sites: Deerlodge Park on the Yampa River (DLP), Island Park on the upper Green (ILP) and Canyonlands National Park on the lower Green (CAN). From these same trees, we took increment cores to understand differences in tree growth in each forest over time. We then related tree metrics to local water availability, streamflow and climatic data. Cottonwoods at CAN were shorter and had lower percent live canopy and growth rate than similarly aged trees upstream. CAN trees that grew higher above the water surface also tended to have lower tree growth, height and live canopy percentage. Furthermore, the correlation between tree growth and maximum vapour pressure deficit showed a much stronger negative shift since 1990 at CAN than at the other sites. All of these differences suggest higher hydrologic stress at CAN, which we attribute to the combined effects of peak flow declines from Flaming Gorge Reservoir, flow diversion and the higher and increasing vapour pressure deficit at CAN. Further research on the variability of hydrologic stress on cottonwoods could help managers anticipate and mitigate the effects of drought stress in these iconic forests. [ABSTRACT FROM AUTHOR]

The aim of this study is to present the outcomes of cerebral aneurysm treatment with the DERIVO® mini Embolisation Device (DMD), which is compatible with microcatheters with 0.021-inch inner diameters. Consecutive patients treated with DMD were identified retrospectively. Patient and aneurysm characteristics, procedural findings, clinical outcomes and follow-up imaging results were evaluated. A total of 44 target aneurysms in 30 patients were treated with DMD. The mean age of the patients was 49.9 (range, 4–77 years). Four patients with five aneurysms presented with acute subarachnoid hemorrhage. The mean aneurysm size was 6.8 mm (range, 1.5–22 mm). In 29 (65.9%) aneurysms, adjunctive devices were used for endovascular treatment. The overall mortality rate was 3.3% and procedure-related mortality was 0%. Overall neurologic morbidity was 6.6% and none of the patients had a permanent sequela secondary to the procedure. The mean clinical follow-up period was 20.9 months (range, 3 days–46 months) and the mean DSA follow-up period was 10.9 months. A total of 37 (84.1%) aneurysms demonstrated total occlusion (Raymond–Roy [RR 1]); 3 (6.8%) aneurysms had a neck remnant or infundibular filling at the origin of the jailed side branch (RR 2), 4 (9.1%) aneurysms had residual aneurysm filling (RR 3). For those aneurysms treated with bare DMD, the total occlusion rate was 73.3% at a mean follow-up of 16.1 months. In this initial clinical single-center experience, DMD had a good safety profile and efficacy comparable with the currently used flow diverters. [ABSTRACT FROM AUTHOR]

Background: MCA bifurcation aneurysms pose treatment challenges because of the complex hemodynamics at the bifurcation and the risk of rupture. FDS implantation has been controversial and there are only limited reports. Therefore, the aim of this study was to assess the efficacy and safety of this treatment strategy using p64 MW HPC and p48 MW HPC FDSs for MCA bifurcation aneurysms, compared with the p64 classic FDS. Materials and methods: We retrospectively analyzed our institutional database and identified all patients with saccular, non-ruptured MCA bifurcation aneurysms treated with p64 MW HPC, p48 MW HPC, or p64 classic FDS implantation alone. Aneurysms with implantation of additional devices in the same session, previous treatments, and acutely ruptured and fusiform aneurysms were excluded. Results: A total of 79 aneurysms met the inclusion criteria: 23 receiving a p64 MW HPC, 34 receiving a p48 MW HPC, and 22 receiving a p64 classic FDS. The occlusion rate was highest for the p48 MW HPC 2 mm FDS, at 88.9% at FU2, compared with 72.2% for the p64 MW HPC and 70.6% for the p64 classic. The time to aneurysm occlusion was shortest with the p64 MW HPC, at 178.31 days. The highest retreatment rate was observed with the p48 MW HPC 3 mm. Conclusion: Treatment of MCA bifurcation aneurysms with a p48 MW HPC 2 mm or p64 MW HPC FDS is a safe and reliable strategy achieving high aneurysm occlusion rates - attributable to their lower porosity in relation to the parent vessel diameter as compared to the p48 MW HPC 3 mm FDS-, with reasonable morbidity and mortality. [ABSTRACT FROM AUTHOR]

Dual antiplatelet therapy (DAPT) use is the standard of practice after flow diversion (FD) for intracranial aneurysms (IAs). Yet, no consensus exists in the literature regarding the optimal regimen. Certain institutions utilize various platelet function testing (PFT) to assess patient responsiveness to DAPT. Clopidogrel is the most commonly prescribed drug during DAPT; however, up to 52% of patients can be non-responders, justifying PFT use. Additionally, prices vary significantly among antiplatelet drugs, often further complicated by insurance restrictions. We aimed to determine the most cost-effective strategy for deciding DAPT regimens for patients after IA treatment. A decision tree with Monte Carlo simulations was performed to simulate patients undergoing various three-month postoperative DAPT regimens. Patients were either universally administered aspirin alongside clopidogrel, ticagrelor, or prasugrel without PFT, or administered one of the former thienopyridine medications based on platelet reactivity unit (PRU) results after clopidogrel. Input data for the model were extracted from the current literature, and the willingness-to-pay threshold (WTP) was defined as $100,000 per QALY as per standard practice in the US. The baseline comparison was with universal clopidogrel DAPT without any PFT. Probabilistic and deterministic sensitivity analyses were performed to evaluate the robustness of the model. Utilizing PFT and switching clopidogrel to prasugrel if resistance is documented was the most cost-effective regimen compared to universal clopidogrel, with a base-case incremental cost-effectiveness ratio (ICER) of $-35,255 (cost $2,336.67, effectiveness 0.85). Performing PFT and switching clopidogrel to ticagrelor (ICER $-4,671; cost $2,995.06, effectiveness 0.84), universal prasugrel (ICER $5,553; cost $3,097.30, effectiveness 0.84), or universal ticagrelor (ICER $75,969; cost $3,801.36, effectiveness 0.84) were all more cost-effective than treating patients with universal clopidogrel (cost $3,041.77, effectiveness 0.83). These conclusions remain robust in probabilistic and deterministic sensitivity analyses. The most cost-effective strategy guiding DAPT after FD for IAs is to perform PFTs and switch clopidogrel to prasugrel if resistance is documented, alongside aspirin. The cost of PFT is strongly justified and recommended when deciding patient-specific DAPT regimens. [ABSTRACT FROM AUTHOR]

Background: Flow diversion has significantly improved the management of cerebral aneurysms. Technological advancements and increased clinical experience over the past decade have led to better outcomes and fewer complications. This study provides updated results and examines the factors that influence the success of flow diversion. Methods: We reviewed records of 115 patients with 121 intracranial aneurysms treated from July 2014 to August 2023. All patients had unruptured aneurysms in the anterior and posterior circulation. Results: Complete aneurysm occlusion was achieved in 72.7% of cases, with a complication rate of 9.1%. Significant predictors of complete occlusion included aneurysm diameter (OR = 0.89, 95% CI 0.82–0.97, p = 0.009) and the presence of incorporated branches (OR = 0.22, 95% CI 0.08–0.59, p = 0.003). Cox analysis identified neck diameter (HR = 0.92, 95% CI 0.87–0.98, p = 0.009) and incorporated branch (HR = 0.40, 95% CI 0.24–0.69, p = 0.001) as significant for occlusion. Multivariable analysis identified aneurysm diameter (OR = 1.21, 95% CI 1.09–1.37, p = 0.001) as significant for safety outcomes. Improved outcomes were observed in recent treatments, with higher occlusion rates (79.7% vs. 61.7%, p = 0.050) and lower complication rates (4.1% vs. 14.9%, p = 0.011). Conclusions: Enhanced technical proficiency, better devices, and refined patient selection have significantly improved the efficacy and safety of flow diversion for cerebral aneurysms. Identifying significant predictors for treatment success and safety outcomes can inform clinical practice, aiding in patient selection. [ABSTRACT FROM AUTHOR]

Flow diversion for intracranial aneurysms emerged as an efficacious and durable treatment option over the last two decades. In a paradigm shift from intrasaccular aneurysm embolization to parent vessel remodeling as the mechanism of action, the proliferation of flow-diverting devices has enabled the treatment of many aneurysms previously considered untreatable. In this review, we review the history and development of flow diverters, highlight the pivotal clinical trials leading to their regulatory approval, review current devices including endoluminal and intrasaccular flow diverters, and discuss current and expanding indications for their use. Areas of clinical equipoise, including ruptured aneurysms and wide-neck bifurcation aneurysms, are summarized with a focus on flow diverters for these pathologies. Finally, we discuss future directions in flow diversion technology including bioresorbable flow diverters, transcriptomics and radiogenomics, and machine learning and artificial intelligence. [ABSTRACT FROM AUTHOR]

Advances in the use of flow diversion (FD) now extend to bifurcation aneurysms; herein, we compare thromboembolic events in patients with internal carotid artery (ICA) aneurysms treated with and without exclusion of the anterior cerebral artery (ACA). Retrospective analysis of aneurysms in the terminal ICA treated with FD from 2013 to 2023 at a single-center study. Procedures were classified according to the coverage at the origin of the ACA and compared through bivariate-analysis. A review was also carried on PubMed, Web of Science, and EMBASE until April 2024, adhering to the PRISMA reporting guidelines. Ninety-five patients harboring 113 aneurysms treated in 102 procedures were evaluated. Fifty-eight were treated covering the ACA origin. Dual antiplatelet regimens included aspirin-clopidogrel (50%), aspirin-ticagrelor (44.1%), and aspirin-prasugrel (4.9%). Thromboembolic events occurred in 6 patients (5.9%), all of which presented with large vessel occlusion of the ICA, but without reaching statistical difference in the 2 treated cohorts (P = 0.46). At a median clinical follow-up of 5.95 months, there were no differences in the functional outcomes in the 2 groups (P = 0.22). Contralateral angiographic runs post-treatment after covering the ACA origin demonstrated increase in the A1 (median: 0.45 mm; IQR = 0.4–1.2) and ICA diameter (median: 0.55 mm; IQR = 0.1–1.2). After pooling data from literature and our cohort, complete side branch occlusion after the coverage of ACA was seen in 25% of branches (95%CI = 0.16–0.36), and thromboembolic events were observed after 3% (95%CI = 0.01–0.04) of procedures. Thromboembolic events can occur in distal ICA aneurysms treated with FD, but no significant association was seen with covering the ACA origin. [ABSTRACT FROM AUTHOR]

Flow diversion for bifurcation aneurysms requires excluding one of the branches from the parent artery, raising concern for ischemic events. We evaluated thromboembolic events and their relationship with covering the origin of the posterior cerebral artery (PCA). This retrospective analysis included patients with confirmed basilar and proximal PCA aneurysms treated with flow diversion between 2013 and 2023. Procedures were classified according to the coverage of the origin of the PCA. Thromboembolic events associated with the excluded PCA were evaluated. Of the total 28 aneurysms included, 7 were at the basilar tip, 16 in the basilar trunk, and 5 in the first segment of the PCA; 15 were treated by excluding one of the PCAs. Dual antiplatelet therapy included aspirin and ticagrelor (57.1%), aspirin and clopidogrel (35.7%), or aspirin and prasugrel (3.57%). Complete and near-complete aneurysm occlusion was achieved in 80.8% of the aneurysms treated at a median follow-up of 12.31 months. Thromboembolic complications occurred in 3 patients (2 with basilar perforator stroke and 1 with basilar in-stent thrombosis). However, the difference in these events was not statistically significant between patients with PCA coverage and those without (P = 0.46). Diminished flow and a lack of flow was seen in 8 and 7 of the covered vessels, respectively. A modified Rankin scale score of ≤2 was reported for 89.3% of patients at a median clinical follow-up of 5.5 months. The incidence of thromboembolic events is high in distal basilar and proximal PCA aneurysms; however, PCA coverage was not associated with their occurrence. There was no difference in postprocedural disability between patients whose aneurysms were treated by excluding one of the PCAs and those who were not. [ABSTRACT FROM AUTHOR]

This comprehensive review delves into the evolving field of neurointervention for intracranial aneurysms, exploring the critical adjunct of Dual Antiplatelet Therapy (DAPT) to endovascular coiling, stent-assisted coiling (SAC), flow-diversion stents, and flow-disruption (intrasaccular) devices. Despite growing evidence supporting the success of DAPT in reducing thromboembolic events, the lack of consensus on optimal regimens, doses, and duration is evident. Factors contributing to this variability include genetic polymorphisms affecting treatment response and ongoing debates regarding the clinical significance of hemorrhagic complications associated with DAPT. This review analyzes pre- and post-procedural antiplatelet usage across various interventions. The imperative lies in ongoing research to define optimal DAPT durations, ensuring a nuanced approach to the delicate balance between thrombosis and hemorrhage in intracranial aneurysm management. [ABSTRACT FROM AUTHOR]

This comprehensive review explores the multifaceted role of endothelial progenitor cells (EPCs) in vascular diseases, focusing on their involvement in the pathogenesis and their contributions to enhancing the efficacy of endovascular treatments for intracranial aneurysms (IAs). Initially discovered as CD34+ bone marrow-derived cells implicated in angiogenesis, EPCs have been linked to vascular repair, vasculogenesis, and angiogenic microenvironments. The origin and differentiation of EPCs have been subject to debate, challenging the conventional notion of bone marrow origin. Quantification methods, including CD34+ , CD133+ , and various assays, reveal the influence of factors, like age, gender, and comorbidities on EPC levels. Cellular mechanisms highlight the interplay between bone marrow and angiogenic microenvironments, involving growth factors, matrix metalloproteinases, and signaling pathways, such as phosphatidylinositol-3-kinase (PI3K) and mitogen-activated protein kinase (MAPK). In the context of the pathogenesis of IAs, EPCs play a role in maintaining vascular integrity by replacing injured and dysfunctional endothelial cells. Recent research has also suggested the therapeutic potential of EPCs after coil embolization and flow diversion, and this has led the development of device surface modifications aimed to enhance endothelialization. The comprehensive insights underscore the importance of further research on EPCs as both therapeutic targets and biomarkers in IAs. [ABSTRACT FROM AUTHOR]

Objective: Comparison of the results of stent-assisted coiling (SAC) with braided stents (BS), flow diverters (FD), and laser-cut stents (LCS) to determine the relative flow-diverting capacity of BS (Leo baby and Accero). Methods: Saccular intracranial aneurysms treated by SAC and FD-assisted coiling were retrospectively evaluated. Aneurysm occlusion, as graded per Raymond–Roy score, was categorized as either recanalization/stable residual filling (Group A; lacking a flow diversion effect) or stable/progressive occlusion (Group B with a "flow diversion effect"). Factors predicting the flow diversion effect were evaluated. Results: Of the 194 aneurysms included, LCS, BS, and FD were used in 70 (36.1%), 86 (44.3%), and 38 (19.6%) aneurysms, respectively. Aneurysms treated by FD were larger, had wider necks, and were located on larger parent arteries (p < 0.01, 0.02, and <0.01, respectively). The mean imaging follow-up duration was 24.5 months. There were 29 (14.9%) aneurysms in Group A and 165 (85.1%) in Group B. Among a spectrum of variables, including sex, age, aneurysm size, neck width, parent artery diameter, follow-up duration, and stent type, the positive predictors for stable/progressive aneurysm occlusion were aneurysm size and placement of an FD or BS (p < 0.01 and p < 0.01, respectively, and were positive predictors over LCS: ORs 6.34 (95% CI: 1.62–24.76) and 3.11 (95% CI: 1.20–8.07), respectively) in multivariate analysis. Conclusions: The placement of BS was a predictor of flow diversion over laser-cut stents. However, the flow diversion effect was approximately half that of FDs, suggesting that BS may only be considered to have some (partial) flow diversion effects. [ABSTRACT FROM AUTHOR]

Extensive research has confirmed the safety and effectiveness of flow diverters in the treatment of unruptured intracranial aneurysms. However, their use in cases of acute rupture remains a subject of debate. This study was conducted as a single-center retrospective investigation from January 2018 to January 2022 and included patients with acutely ruptured intracranial aneurysms (within three days of rupture) who were treated using the Pipeline Embolization Device with adjunctive coil embolization. Patient demographics, operative procedures, and outcomes were analyzed. Antiplatelet therapy included intra-arterial tirofiban and postoperative dual therapy with clopidogrel and aspirin. A total of 21 patients (5 males, 16 females) diagnosed with acutely ruptured intracranial aneurysms were included in this study. The aneurysm types included 7 blood blister-like aneurysms (30.0%), 3 dissecting (14.3%), and 1 fusiform aneurysm (4.8%). Perioperative complications occurred in 2 patients (9.5%), and both cases involved thrombogenesis. Nineteen patients completed digital subtraction angiography during follow-up, with an average follow-up time of 8.7 months (5 − 18 months). Results showed a complete embolization rate of 94.7% (18/19), with a partial aneurysm still present in 1 patient. A total of 90.4% (19/21) of patients had a favorable prognosis (modified Rankin Scale score = 0 − 2). The Pipeline Embolization Device with adjunctive coil embolization proved to be a viable option for managing acutely ruptured intracranial aneurysms, notwithstanding the potential for ischemic complications. [ABSTRACT FROM AUTHOR]

Background Flow diversion has revolutionized the management of wide‐necked intracranial aneurysms (IAs). We aimed to assess the effectiveness and safety of the new generation 64‐wire Surpass Evolve for the treatment of unruptured small/medium‐sized IAs. Methods and Results This is a subanalysis from the SEASE (Safety and Effectiveness Assessment of the Surpass Evolve) registry, an observational cohort study including 15 academic institutions in North America and Europe between July 2020 and October 2022. Patients with wide‐necked saccular IAs, measuring

Background The presence of an incorporated branch as well as its anatomical relationship to the intracranial aneurysms (IAs) and the parent artery may affect the occlusion outcome following flow diversion. This study evaluated the safety and effectiveness of the cobalt‐chromium Surpass Evolve (Stryker), a 64‐wire flow diversion device for the treatment of IAs with incorporated branches. Methods This subanalysis uses data from the SEASE (Safety and Effectiveness Assessment of Surpass Evolve) registry to retrieve data related to IAs with incorporated branches. Those IAs were classified by a core lab into 4 categories based on their anatomical relationship to the parent artery and branch: (A) sidewall anatomic, (B) sidewall hemodynamic, (C) neck branch, and (D) dome branch. We compared the outcomes based on their incorporated branch's relation to the dome (A–C versus D). Results This study included 67 patients and IAs. Most IAs were in the posterior communicating artery (46.3%), with a median size of 4.35 mm. Age, sex, comorbidities, baseline functional‐status, and IA features were similar between the 2 groups. Among those, 53 (79.1%) had branches emerging from the dome, and 14 (20.9%) had branches originating from other locations (A = 7, B = 2, and C = 5). At a median imaging follow‐up of 10.5 months, complete occlusion was lower in IAs with a branch from the sac compared with those with the neck (60.8% versus 92.9%; P = 0.026), with an overall occlusion of 67.7%. Thromboembolic and hemorrhagic complications, as well as retreatment, were reported in 1.6% and 3.1% of cases, respectively, with no significant differences between groups. Conclusion Our analysis underscores the influence of branch origin on occlusion rates, with the neck‐originating branch demonstrating higher occlusion rates. These insights emphasize the role of anatomical considerations in treatment strategies, follow‐up timelines, and designing future clinical trials. Further studies are warranted to explore these variations across different flow diversion technologies.

Background Direct endoluminal imaging, such as with our previously described microangioscope, is an emerging adjunct in endovascular cerebral aneurysm management that enables clinicians to delineate between thrombi and visualize neoepithelialization after stent placement with high resolution. The present study sought to study flow diversion in vivo under direct endoluminal imaging, and to validate our findings with histopathology. Methods In a rabbit model, we implanted each left common carotid artery with a shielded flow diverter (FD) (Medtronic Pipeline Vantage) and nonshielded FD (Medtronic Pipeline Flex) in the right common carotid artery. We studied 9 animals in 3 groups: (1) no periprocedural antiplatelet therapy, (2) aspirin 81 mg daily, and (3) aspirin 81 mg and clopidogrel 75 mg daily. FD thrombosis, stenosis, malapposition, and neoepithelialization were all evaluated by diagnostic cerebral angiography and microangioscopy after 30 days. Diagnostic cerebral angiography and angioscopic video were analyzed by independent evaluators and compared with histopathologic analysis. Results In the aspirin and dual antiplatelet therapy groups, there were no significant observed differences in stent thrombosis, stenosis, malapposition, or neoepithelialization between the shielded and non‐shielded FD groups. There was significantly more thrombus formation in Group 1. Neointimal thickness as measured by the microangioscope was highly correlated with histology (r = 0.72; P = 0.016). Interrater agreement of microangioscope videos was highest for FD thrombosis and stenosis. Conclusion In‐stent thrombosis, stenosis, malapposition, and neopithelialization demonstrated no significant difference between shielded and non‐shielded FDs. Microangioscopy measurements for neointimal thickness were highly correlated with pathology and may be a helpful adjunct to diagnostic cerebral angiography in FD follow‐up.

Background Flow diversion (FD) has emerged as an effective treatment option for intracranial aneurysms. However, there is limited evidence regarding its safety and efficacy specifically for distal and small‐artery aneurysms of the posterior circulation. This study aimed to investigate the outcomes of FD for aneurysms arising from the posterior inferior cerebellar artery, anterior inferior cerebellar artery, superior cerebellar artery, and the P2 and P3 segments of the posterior cerebral artery. Methods This is a subanalysis of the Post‐FD (Posterior Circulation Aneurysms Treated With Flow Diversion) registry, highlighting distal aneurysms in the posterior inferior cerebellar artery, anterior inferior cerebellar artery, superior cerebellar artery, and the P2 and P3 segments of the posterior cerebral artery treated with FD. Aneurysm characteristics and patient outcomes were described for the total series, and a more focused analysis comparing fusiform/dissecting versus saccular aneurysms was performed. The primary treatment outcome was complete aneurysm occlusion (Raymond–Roy class 1). Primary safety outcome was major ischemic/hemorrhagic stroke following FD. Secondary outcomes included functional outcome, aneurysm retreatment, and in‐stent stenosis. Results Overall, 36 patients with 36 aneurysms were treated with FD, with a median age of 60.0 years (interquartile range [IQR], 52.8—65.3 years). Of those, 13 were fusiform/dissecting, while 23 were saccular aneurysms. Complete occlusion was achieved in 78.1% for all aneurysms at a median follow‐up of 14.0 months (IQR, 9.3–48.6 months). There was a nonsignificant trend in rates of complete occlusion between fusiform/dissecting (91.7%) and saccular aneurysms (70%; P = 0.151). Major stroke was reported in 2 cases (5.6%) and in‐stent stenosis in 4 (11.1%), and retreatment was required for 4 aneurysms (11.4%) There was no difference in rates of major stroke, in‐stent stenosis, or retreatment between fusiform/dissecting and saccular aneurysms. Conclusion This study suggests the safety and feasibility of FD for distal aneurysms of the posterior circulation, particularly fusiform/dissecting aneurysms. Further larger‐scale studies are warranted to confirm these findings.

Parent vessel occlusion (PVO) is a time-honored treatment for unclippable or uncoilable intracranial aneurysms. Flow diversion (FD) is a recent endovascular alternative that can occlude the aneurysm and spare the parent blood vessel. Our aim was to compare outcomes of FD with endovascular PVO. This is a prespecified treatment subgroup analysis of the Flow diversion in Intracranial Aneurysms trial (FIAT). FIAT was an investigator-led parallel-group all-inclusive pragmatic randomized trial. For each patient, clinicians had to prespecify an alternative management option to FD before stratified randomization. We report all patients for whom PVO was selected as the best alternative treatment to FD. The primary outcome was a composite of core-lab determined angiographic occlusion or near-occlusion at 3–12 months combined with an independent clinical outcome (mRS<3). Primary analyses were intent-to-treat. There was no blinding. There were 45 patients (16.2% of the 278 FIAT patients randomized between 2011 and 2020 in 3 centers): 22 were randomly allocated to FD and 23 to PVO. Aneurysms were mainly large or giant (mean 22 mm) anterior circulation (mainly carotid) aneurysms. A poor primary outcome was reached in 11/22 FD (50.0%) compared to 9/23 PVO patients (39.1%) (RR: 1.28, 95% CI [0.66–2.47]; P = 0.466). Morbidity (mRS >2) at 1 year occurred in 4/22 FD and 6/23 PVO patients. Angiographic results and serious adverse events were similar. The comparison between PVO and FD was inconclusive. More randomized trials are needed to better determine the role of FD in large aneurysms eligible for PVO. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the clinical course after flow diversion (FD) treatment with a focus on aneurysms with remnant sac filling, by analyzing angiographic outcomes, aneurysm volume, and clinical events. We retrospectively reviewed the medical records of 61 patients who underwent FD for intracranial aneurysms between July 2014 and June 2021. The 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 FD, 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. Aneurysm enlargement after FD 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 FD. [ABSTRACT FROM AUTHOR]

Background and purpose: Flow diverter embolization is a recognized method for treating intracranial aneurysms. This study evaluates the safety and efficacy of the Surpass Evolve flow diverter in treating intracranial aneurysm. Material and methods: From May 2019 to June 2022, our center prospectively enrolled patients presenting with both ruptured and unruptured intracranial aneurysms. We assessed aneurysm occlusion, along with the occurrence of ischemic and hemorrhagic complications, and mortality at 6-months. The 3-month occlusion rate was determined using MR angiography, while the 6-month occlusion rate employed the O'Kelly–Marotta (OKM) grading scale on DSA. Results: A total of 116 patients with 120 aneurysms received treatment with the Surpass Evolve device. The average aneurysm size was 6.6 mm (range: 2-30 mm). All patients were administered two loading doses of ticagrelor (180 mg) one day before the procedure and 2 h pre-embolization. A procedural complication occurred in one case, involving wire-related perforation of an M3 branch distant from the giant aneurysm; however, this evolved favorably. There were no reported deaths linked to the treatment. Permanent neurological deficits were observed in 3 (2.5%) patients, primarily due to early in-stent thrombosis. MR angiography results at 3 months indicated complete occlusion for 87 out of 115 (75.6%) monitored aneurysms. The 6-month DSA showed neck remnant or complete occlusion (OKM grade C or D) in 86 out of the 107 (80.4%) patients who underwent follow-up. Conclusion: The Surpass Evolve stands out as a reliable and effective flow diverter for the management of intracranial aneurysms. [ABSTRACT FROM AUTHOR]

Purpose: Flow-diverter (FD) stents have become an established treatment for intracranial aneurysms in recent years, but their use for aneurysms in distal cerebral vessels with small carrier vessel diameters remains controversial. This study describes the method and mid- and long-term outcomes of FD treatment of distal anterior cerebral artery aneurysms (DACAAs) at two neurointerventional centers, to elucidate this topic and provide more in-depth data. Methods: Data for all patients at two neurointerventional centers who were treated with FDs for DACAAs in the pericallosal and supracallosal segment of the anterior cerebral artery were retrospectively analyzed. Data on periprocedural complications, and short-, mid- and long-term follow-up findings were recorded. Results: Forty-one patients were eligible for inclusion in the study. Three FD models were used, one of which had an anti-thrombotic coating. Two periprocedural complications (5%) occurred but did not cause a change in the mRS. In the long-term follow-up, at 29 months and beyond, 83% of assessable patients showed complete occlusion of the aneurysms without new neurological deficits. Conclusion: FDs are a safe and effective treatment approach for DACAAs. This study indicated a low risk of complications, and high closure rates in short-, mid- and long-term follow-up. [ABSTRACT FROM AUTHOR]

Background: The use of antithrombotic medication following acute flow diversion for a ruptured intracranial aneurysm (IA) is challenging with no current guidelines. We investigated the incidence of treatment-related complications and patient outcomes after flow diversion for a ruptured IA before and after the implementation of a standardized antithrombotic medication protocol. Methods: We conducted a single-center retrospective study including consecutive patients treated for acutely ruptured IAs with flow diversion during 2015–2023. We divided the patients into two groups: those treated before the implementation of the protocol (pre-protocol) and those treated after the implementation of the protocol (post-protocol). The primary outcomes were hemorrhagic and ischemic complications. A secondary outcome was clinical outcome using the modified Ranking Scale (mRS). Results: Totally 39 patients with 40 ruptured IAs were treated with flow diversion (69% pre-protocol, 31% post-protocol). The patient mean age was 55 years, 62% were female, 63% of aneurysms were in the posterior circulation, 92% of aneurysms were non-saccular, and 44% were in poor grade on admission. Treatment differences included the use of glycoprotein IIb/IIIa inhibitors (pre-group 48% vs. post-group 100%), and the use of early dual antiplatelets (pre-group 44% vs. 92% post-group). The incidence of ischemic complications was 37% and 42% and the incidence of hemorrhagic complications was 30% and 33% in the pre- and post-groups, respectively, with no between-group differences. There were three (11%) aneurysm re-ruptures in the pre-group and none in the post-group. There were no differences in mortality or mRS 0–2 between the groups at 6 months. Conclusion: We found no major differences in the incidence of ischemic or hemorrhagic complications after the implementation of a standardized antithrombotic protocol for acute flow diversion for ruptured IAs. There is an urgent need for more evidence-based guidelines to optimize antithrombotic treatment after flow diversion in the setting of subarachnoid hemorrhage. [ABSTRACT FROM AUTHOR]

The collar sign has been previously described as an angiographic indicator of incomplete occlusion after deployment of a pipeline embolization device (PED) for intracranial aneurysms. In the present study, we explore the predictors for a collar sign in aneurysms treated with the PED. Aneurysms with a collar sign at the initial follow-up angiogram were identified in a retrospective review of single-center data. The predictors of a collar sign were analyzed through univariate and multivariate analyses. A total of 492 cases of cerebral aneurysm treated with the PED were identified. Among them, 53 were found to have a collar sign on the initial follow-up angiogram. Univariate analysis showed that previous treatment of the same aneurysm (odds ratio [OR], 2.46; P = 0.01), a branch vessel from the aneurysm neck or dome (OR, 6.2; P < 0.001), and a smaller aneurysm neck size (OR, 0.75; P = 0.01) were all predictors for the presence of a collar sign. A larger diameter (OR, 0.92; P = 0.06), increased dome/neck ratio (OR, 1.38; P = 0.1), increased aspect ratio (OR, 1.14; 0 P =.17), and previous treatment showed a trend toward an association with a collar sign. However, after multivariate analysis, a branch from the aneurysm neck or dome (OR, 6.23; P < 0.001), aneurysm diameter (OR, 0.75; P = 0.032), an increased dome/neck ratio (OR, 4.62; P = 0.006), and previous treatment were the strongest predictors for a collar sign. The presence of a branch vessel arising from the aneurysm neck or dome, an increased dome/neck ratio, aneurysm diameter, and previous treatment are the strongest predictive factors for a collar sign in the angiographic follow-up of PED-treated aneurysms. [ABSTRACT FROM AUTHOR]

The Pipeline Embolization Device (PED) is a flow-diverting intraluminal device that is approved for use in adults 18 years or older with internal carotid artery aneurysms. However, it can also be used off-label in pediatric patients with aneurysms that cannot be resolved with traditional endovascular treatments. Herein, we present two cases of flow diversion in the pediatric population with complete obliteration of the aneurysm and excellent outcomes. Flow diversion has been shown to be a safe endovascular option in treating complex aneurysms in children. Larger-sized, multicenter trials are encouraged to compare outcomes between flow diversion and other aneurysm treatment options given the rarity of pediatric aneurysms. [ABSTRACT FROM AUTHOR]

We present a case of intracranial aneurysm located in the P1 segment of left posterior cerebral artery in the context of tetralogy of Fallot. Complex variations included right aortic arch with abnormal branching. Also, the bilateral vertebral arteries were absent, with a type I persistent proatlantal intersegmental artery of the left side. The aneurysm was treated with endovascular intervention with a Tubridge flow diverter and was noted to be completely cured on 6-month follow-up. We discuss the many considerations in this patient including developmental and modern-era treatment. [ABSTRACT FROM AUTHOR]

BackgroundMCA bifurcation aneurysms pose treatment challenges because of the complex hemodynamics at the bifurcation and the risk of rupture. FDS implantation has been controversial and there are only limited reports. Therefore, the aim of this study was to assess the efficacy and safety of this treatment strategy using p64 MW HPC and p48 MW HPC FDSs for MCA bifurcation aneurysms, compared with the p64 classic FDS.Materials and methodsWe retrospectively analyzed our institutional database and identified all patients with saccular, non-ruptured MCA bifurcation aneurysms treated with p64 MW HPC, p48 MW HPC, or p64 classic FDS implantation alone. Aneurysms with implantation of additional devices in the same session, previous treatments, and acutely ruptured and fusiform aneurysms were excluded.ResultsA total of 79 aneurysms met the inclusion criteria: 23 receiving a p64 MW HPC, 34 receiving a p48 MW HPC, and 22 receiving a p64 classic FDS. The occlusion rate was highest for the p48 MW HPC 2 mm FDS, at 88.9% at FU2, compared with 72.2% for the p64 MW HPC and 70.6% for the p64 classic. The time to aneurysm occlusion was shortest with the p64 MW HPC, at 178.31 days. The highest retreatment rate was observed with the p48 MW HPC 3 mm.ConclusionTreatment of MCA bifurcation aneurysms with a p48 MW HPC 2 mm or p64 MW HPC FDS is a safe and reliable strategy achieving high aneurysm occlusion rates - attributable to their lower porosity in relation to the parent vessel diameter as compared to the p48 MW HPC 3 mm FDS-, with reasonable morbidity and mortality.

Abstract Background Second-stage flow diversion with coil embolization may improve occlusion outcomes and reduce periprocedural complications in patients with cerebral aneurysm. However, the actual cause behind this is unclear. In this study, we aimed to compare the efficacy and safety of second-stage pipeline embolization device (PED) and single-stage PED with coil embolization. Results Of the 22 treated patients with aneurysm, 10 and 12 were treated with second-stage PED and single-stage PED with coil embolization, respectively. The mean follow-up duration was 29.6 months. The mean numbers of diffusion-weighted image (DWI)-positive spots on day 1 post-procedure were 4.9 and 10.8 in the second-stage and single-stage PED with coil embolization groups, respectively (P = 0.01). Deterioration of the modified Rankin scale score was not ≥ 2 in any patient during follow-up in the second-stage PED group but was observed in 16.7% of cases (2/12) in the single-stage PED with coil embolization group (P = 0.48). On follow-up angiography, complete occlusion was observed in all patients (10/10) in the second-stage PED group and 66.7% (8/12) in the single-stage PED with coil embolization group (P = 0.09). Conclusions The second-stage PED strategy significantly reduces the number of DWI high-intensity spots, leading to the prevention of ischemic complications. This strategy may help to prevent complications and reduce morbidity.

The aim of this study is to present the outcomes of cerebral aneurysm treatment with the DERIVO® mini Embolisation Device (DMD), which is compatible with microcatheters with 0.021-inch inner diameters. Consecutive patients treated with DMD were identified retrospectively. Patient and aneurysm characteristics, procedural findings, clinical outcomes and follow-up imaging results were evaluated. A total of 44 target aneurysms in 30 patients were treated with DMD. The mean age of the patients was 49.9 (range, 4–77 years). Four patients with five aneurysms presented with acute subarachnoid hemorrhage. The mean aneurysm size was 6.8 mm (range, 1.5–22 mm). In 29 (65.9%) aneurysms, adjunctive devices were used for endovascular treatment. The overall mortality rate was 3.3% and procedure-related mortality was 0%. Overall neurologic morbidity was 6.6% and none of the patients had a permanent sequela secondary to the procedure. The mean clinical follow-up period was 20.9 months (range, 3 days–46 months) and the mean DSA follow-up period was 10.9 months. A total of 37 (84.1%) aneurysms demonstrated total occlusion (Raymond–Roy [RR 1]); 3 (6.8%) aneurysms had a neck remnant or infundibular filling at the origin of the jailed side branch (RR 2), 4 (9.1%) aneurysms had residual aneurysm filling (RR 3). For those aneurysms treated with bare DMD, the total occlusion rate was 73.3% at a mean follow-up of 16.1 months. In this initial clinical single-center experience, DMD had a good safety profile and efficacy comparable with the currently used flow diverters.

Anterior inferior cerebellar artery (AICA) aneurysms present a challenge for neurosurgeons and neurointerventionalists alike. Cases of AICA aneurysms managed with endovascular flow diversion at our institute are reviewed with their angiographic outcomes. Both direct and indirect flow diversion provide complete aneurysm occlusion at follow-up. We propose a stratified method of approaching AICA aneurysms based on location, rupture status, and neck size. Careful evaluation of preoperative parameters is paramount in deciding between a surgical or a neuroendovascular approach. Low-profile stents in the future may assist in direct flow diversion of AICA trunk aneurysms. In addition, neurosurgeons need to be well versed in endovascular approaches. [ABSTRACT FROM AUTHOR]

Background: Traumatic intracranial aneurysms (TICAs) constitute a notable portion of pediatric intracranial aneurysms. Their unstable structure dictates a high incidence of rupture or mass effect from enlarging unruptured aneurysms, necessitating prompt diagnosis and treatment. TICAs often lack a true neck or are wide-necked, making them unsuitable for coil embolization and surgical clipping, and their fragile nature poses a risk of rupture during surgical and intrasaccular interventions. Endoluminal flow diverters (FD), deployed without requiring direct access to the aneurysmal sac, have emerged as an appealing sole treatment modality for TICAs. However, the clinical experience with this technique remains limited in the pediatric population. Method: We describe the successful treatment of a paraclinoid TICA in a 4-year-old female using an endoluminal FD alone. Additionally, we conducted a literature review to assess the safety and effectiveness of this treatment modality in pediatric TICAs. Results: Endoluminal flow diversion led to complete aneurysm obliteration in our case, with no observed complication, at the 9-month follow-up. Our review of the previously reported pediatric TICAs managed by standalone flow diversion highlights this technique as safe, efficient, and promising as a sole treatment modality, particularly in the anterior circulation, with a high rate of persistent total obliteration and a low rate of complications. However, the requirement for long-term antiplatelet therapy with the possibility of frequent dose monitoring and adjustments warrants special attention when using endoluminal FDs. Until guidelines specifically addressing optimal antiplatelet therapy in children with intracranial FDs are formulated, adherence to existing protocols is imperative to avoid in-stent thrombosis. Conclusion: Our literature review and personal experience indicate that endoluminal flow diversion can be a viable treatment approach for pediatric TICAs. However, prospective studies with extensive follow-ups are required to assess the durability of endoluminal FDs in treating pediatric TICAs, considering the long life expectancy of this demographic. [ABSTRACT FROM AUTHOR]

Background: Blister aneurysms are high-risk intracranial vascular lesions. Definitive treatment of these lesions has been challenging. Severe disability or mortality rates are as high as 55% when these lesions are treated with open surgery. Recent data show that flow diversion is a safe and effective alternative treatment for blister aneurysms. Rerupture of the functionally unsecured lesion remains a concern as flow diversion does not immediately exclude the aneurysm from the circulation. Methods: A retrospective review was performed of any patients with ruptured blister aneurysms treated with a pipeline embolization device between 2010 and 2020 at the University of Colorado. Results: In this paper, we present the results of the intensive care management of ruptured intracranial blister aneurysms after flow-diverting stent placement. Conclusion: Despite the need for dual antiplatelet therapy and the delayed occlusion of blister aneurysms treated with flow diversion, we did not find an increase in periprocedural complications. [ABSTRACT FROM AUTHOR]

Stenting with flow diverter devices (FDDs) has increasingly emerged as a treatment for intracranial aneurysms. The use of FDDs in the developing world has not been described. A retrospective review was performed of a cohort of patients who underwent flow diversion at 4 tertiary-care centers in Lima, Peru between January 2017 and June 2021. Demographics, clinical features, and aneurysm morphology were evaluated. Clinical outcomes were observed 3 months after discharge and occlusion rates were assessed 12 months after treatment. Sixty-nine patients (mean age, 46 ±14.5 years; 17% female) were treated with FDDs; 4% (n = 3) of the treated aneurysms were ruptured. Most aneurysms were saccular (n = 65; 94%), <10 mm in maximum size (n = 60; 87%), and located in the anterior circulation (n = 67; 97%). Minor complications, such as groin hematoma, occurred in 7 cases. No serious complications or deaths occurred. Patients' functional status was excellent (modified Rankin Scale score 0–1) in 99% (n = 66) at discharge and 100% (n = 67) at 3 months. Although some patients were lost to follow-up, complete occlusion was seen in 76% (n = 31) of 41 treated patients at 12 months. We report the largest multicenter experience of FDDs for cerebral aneurysm treatment in Peru, with reasonable outcomes that are comparable to other settings despite various challenges, suboptimal circumstances, and lack of resources. [ABSTRACT FROM AUTHOR]

Pseudoaneurysms of the posterior circulation pose a unique management challenge. The fragile nature of the pseudoaneurysm wall presents a high risk of rupture and demands treatment. Small vasculature, particularly distal in the posterior circulation, can preclude management with traditional flow diverters, where the alternative of vessel sacrifice is unacceptable. Small stents can have flow-diversion properties and can be used in these high-risk, difficult-to-access aneurysms. We describe a 40-year-old woman presenting with a ruptured dissecting right superior cerebellar artery pseudoaneurysm after minor trauma. Given the aneurysm's small size and morphology, it was not amenable to coiling and parent vessel sacrifice was potentially morbid. The pseudoaneurysm was initially stabilized with a Low-Profile Visualized Intraluminal Support Junior (LVIS Jr.) stent due to its reported flow-diverting properties. At six-month follow-up the pseudoaneurysm was stable and the vasospasm had resolved. At this point, definitive treatment with a "FRED Jr." (Flow Re-Direction Endoluminal Device Junior) flow diverter was pursued. Complete obliteration of the pseudoaneurysm was seen at 12 months' follow-up after staged treatment. Due to the unique challenges associated with ruptured pseudoaneurysms located on small-caliber vessels, the options for definitive treatment are limited. The small size of the LVIS Jr. stent and its flow-diverting properties make it a practical treatment option in a difficult situation. This case report provides further support for the flow-diverting properties of the LVIS Jr. and its potential application in the treatment of ruptured pseudoaneurysms in small-caliber intracranial vessels. [ABSTRACT FROM AUTHOR]

Background and Purpose: Flow diversion of intracranial aneurysms with the Pipeline Embolization Device (PED) is frequently performed, but the outcomes of retreatment for aneurysms that failed to occlude after prior treatment with PED have not been well studied. Here, we report the safety and efficacy of PED retreatment after initial failure to occlude. Materials and Methods: Clinical and angiographic data from eligible patients were retrospectively assessed for demographics, aneurysm occlusion status, and clinical outcomes. Patients were included in this study if they underwent PED retreatment to treat an aneurysm that had previously been treated with PED. Results: Retreatment of previously flow-diverted aneurysms with PED was performed in 42 cases. At final angiographic follow-up, angiographic improvement was observed after 45% (19/42) of retreatments and complete aneurysm occlusion was observed following 26% (11/42). Significant clinical complications occurred in 10% (4/42) of PED retreatments. Conclusions: Retreatment of intracranial aneurysms with PED following initial failure to achieve aneurysm occlusion has a low rate of subsequent complete aneurysm occlusion. [ABSTRACT FROM AUTHOR]

Nuisance bleeding (NB) without urgent medical attention is rarely characterized despite its frequent occurrence in patients with cerebral aneurysms undergoing flow diversion (FD) who are maintained on dual antiplatelet therapy (DAPT). This study explored the risk factors for NB. Patients with unruptured cerebral aneurysms who underwent intervention using FD (July 2018 to May 2022) and had follow-up data were enrolled. Patient demographics, clinical characteristics, aneurysm features and follow-up data were analysed. Bleeding complications were classified as NB, internal bleeding and alarming bleeding. NB was characterized by easy bruising, bleeding from small cuts and nonfatal petechiae and ecchymosis. Univariate and multivariate logistic regression analyses were performed to determine risk factors for NB. This study assessed 121 patients. Of these, 52 (43.0%) patients had NB. Compared with the non-bleeding group, the NB group had more females (82.7% vs. 56.5%; p = 0.003), lower smoking rate (7.7% vs. 23.2%; p = 0.027) and smaller aneurysms (6.65 mm [4.60–9.60 mm] vs. 8.82 mm [5.65–15.65 mm]; p = 0.007) and had more patients maintained on ticagrelor-containing DAPT regimen (90.4% vs. 66.7%; p = 0.002). Multivariate logistic regression revealed that ticagrelor-containing DAPT regimen (odds ratio, 3.91; 95% confidence interval, 1.29–11.87; p = 0.016) was associated with NB. These results suggest that NB is a common bleeding complaint in patients on DAPT. In patients undergoing FD, DAPT with ticagrelor was the only independent risk factor for NB. [ABSTRACT FROM AUTHOR]

Purpose: Some aneurysms remain patent after treatment with flow diverters (FD) due to residual blood flow in the aneurysm. Several studies have proposed that branches and residual flow are associated with delayed aneurysm occlusion. We propose that aneurysm isolation (i.e., the complete disconnection of the aneurysm from surrounding vessels) might be a possible factor facilitating aneurysm occlusion. This study aimed to determine if aneurysm isolation was a factor associated with aneurysm occlusion after FD treatment. Methods: We reviewed 80 internal carotid artery (ICA) aneurysms treated with FDs between October 2014 and April 2021. Aneurysm isolation was assessed in high-resolution cone-beam computed tomograms at the end of each treatment. Aneurysms with incorporated branches and those with connections to other branches due to stent malapposition were deemed to be nonisolated. Other factors, such as patient age, sex, anticoagulant use, aneurysm size, adjunct coil use, and the presence of incorporated branches, were considered. The degree of aneurysm occlusion (complete or incomplete) was assessed by follow-up angiograms 12 months after treatment. Results: Complete occlusion was achieved in 57 of 80 aneurysms (71%). Completely occluded aneurysms had a significantly higher ratio of isolation compared to incompletely occluded aneurysms (91.2% vs. 69.6%, P = 0.032). Multivariate logistic regression analysis showed that aneurysm isolation was the sole significant predictor of complete aneurysm occlusion (odds ratio, OR 19.38; 95% confidence interval, CI 2.280–164.657; P = 0.007). Conclusion: Aneurysm isolation is a significant factor contributing to complete occlusion after FD treatment. [ABSTRACT FROM AUTHOR]

Rationale and objectives: The off-label use of flow diverters (FDs) has broadened to include treating aneurysms in posterior circulation (PC). A novel flow diverter, the Tubridge flow diverter (TFD), has been created in China specifically for treating PC aneurysms. However, studies comparing between pipeline embolization device (PED) and TFD are rare. Thus, our study aimed to explore the effectiveness of PED and TFD in the treatment of PC aneurysms using a propensity score matched cohort design. Methods: Retrospective data collection was conducted on patients who underwent treatment with either PED or TFD over the period from 2015 through 2020. Propensity score matching (PSM) was employed to calibrate for patient age; history of ischemic stroke; aneurysm size; morphology; location and neck; number of FDs; parent vessel diameter; and the employment of assisted coiling and balloon techniques. Data on previously ruptured aneurysms was not included in the analysis. A comparison was conducted between the two devices to assess perioperative complications, aneurysm occlusion rates, and functional outcomes. Results: A total of 252 PC aneurysms were treated in 248 patients. Clinical and imaging follow-ups were lost in 26 and 47 patients, respectively. Major perioperative complications occurred in 7.5% of the cases, with favorable clinical outcomes in 91.0% and complete occlusion in 79.1%. Eighty-two (32.5%) aneurysms were treated with TFD, while 170 (67.5%) aneurysms were treated with PED. PSM was used to account for these significant variations, producing 82 matched pairs of unruptured aneurysms treated with PED or TFD. In terms of functional and angiographic outcomes, no significant differences were found between PED and TFD (functional outcome, p = 0.594 and angiographic outcome, p = 0.415). However, more perioperative major complications were found in patients treated with TFD (p = 0.005) compared with those receiving PED. Conclusion: The comparative study of PED and TFD in the treatment of PC aneurysms resulted in positive clinical results and sustained occlusion rates, with acceptable perioperative complications. However, higher quality studies are needed to enhance our understanding of the use of FDs for treating of PC aneurysms.

PurposeFlow-diverter (FD) stents have become an established treatment for intracranial aneurysms in recent years, but their use for aneurysms in distal cerebral vessels with small carrier vessel diameters remains controversial. This study describes the method and mid- and long-term outcomes of FD treatment of distal anterior cerebral artery aneurysms (DACAAs) at two neurointerventional centers, to elucidate this topic and provide more in-depth data.MethodsData for all patients at two neurointerventional centers who were treated with FDs for DACAAs in the pericallosal and supracallosal segment of the anterior cerebral artery were retrospectively analyzed. Data on periprocedural complications, and short-, mid- and long-term follow-up findings were recorded.ResultsForty-one patients were eligible for inclusion in the study. Three FD models were used, one of which had an anti-thrombotic coating. Two periprocedural complications (5%) occurred but did not cause a change in the mRS. In the long-term follow-up, at 29 months and beyond, 83% of assessable patients showed complete occlusion of the aneurysms without new neurological deficits.ConclusionFDs are a safe and effective treatment approach for DACAAs. This study indicated a low risk of complications, and high closure rates in short-, mid- and long-term follow-up.

IntroductionSuccessful treatment of intracranial aneurysms after flow diversion (FD) is dependent on the flow modulating effect of the device. We aimed to investigate the intra-aneurysmal and parent vessel hemodynamic changes, as well as the incidence of silent emboli following treatment with various FD devices.MethodsWe evaluated the appearance of the eclipse sign in nine distinct phases of cerebral angiography before and immediately after FD placement in correlation with aneurysm occlusion. Angiographic and clinical data of consecutive procedures were analyzed retrospectively. Patients who had successful FD procedure without adjunctive coiling, visible eclipse sign on post embolization angiography, and reliable follow-up angiographic data were included in the analysis. Detailed analysis of hemodynamic data from transcranial doppler after FD was performed in selected patients, such as monitoring for silent emboli.ResultsAmong all patients (N = 65) who met inclusion criteria, complete aneurysm occlusion at 12 months was achieved in 89% (58/65). Eclipse sign prior to FD was observed in 42% (27/65) with unchanged appearance in 4.6% (3/65) of the treated patients. None of these three patients achieved complete aneurysm occlusion. Among all analyzed variables, such as aneurysm size, device type used, age, and appearance of the eclipse sign pre- and post-FD, the most reliable predictor of permanent aneurysm occlusion at 12 months was earlier, prolonged, and sustained eclipse sign visibility in more than three angiographic phases in comparison to the baseline (p < 0.001). Elevation in flow velocities within the ipsilateral vascular territory was noted in 70% (9/13), and bilaterally in 54% (7/13) of the treated patients. None of the patients had silent emboli.ConclusionsIntra-aneurysmal and parent vessel hemodynamic changes after FD can be reliably assessed by the cerebral angiography and transcranial doppler with important implications for the prediction of successful treatment.

Background: Flow diversion has significantly improved the management of cerebral aneurysms. Technological advancements and increased clinical experience over the past decade have led to better outcomes and fewer complications. This study provides updated results and examines the factors that influence the success of flow diversion. Methods: We reviewed records of 115 patients with 121 intracranial aneurysms treated from July 2014 to August 2023. All patients had unruptured aneurysms in the anterior and posterior circulation. Results: Complete aneurysm occlusion was achieved in 72.7% of cases, with a complication rate of 9.1%. Significant predictors of complete occlusion included aneurysm diameter (OR = 0.89, 95% CI 0.82–0.97, p = 0.009) and the presence of incorporated branches (OR = 0.22, 95% CI 0.08–0.59, p = 0.003). Cox analysis identified neck diameter (HR = 0.92, 95% CI 0.87–0.98, p = 0.009) and incorporated branch (HR = 0.40, 95% CI 0.24–0.69, p = 0.001) as significant for occlusion. Multivariable analysis identified aneurysm diameter (OR = 1.21, 95% CI 1.09–1.37, p = 0.001) as significant for safety outcomes. Improved outcomes were observed in recent treatments, with higher occlusion rates (79.7% vs. 61.7%, p = 0.050) and lower complication rates (4.1% vs. 14.9%, p = 0.011). Conclusions: Enhanced technical proficiency, better devices, and refined patient selection have significantly improved the efficacy and safety of flow diversion for cerebral aneurysms. Identifying significant predictors for treatment success and safety outcomes can inform clinical practice, aiding in patient selection.