Flow Diverter Device Research Articles

Analysis of perioperative complications of flow-diverter devices in the treatment of unruptured intracranial aneurysms

Objective: To investigate the perioperative adverse events and complications of flow-diverter devices in the treatment of unruptured intracranial aneurysms. Methods: This is a retrospective case series study. The clinical and imaging data of 174 patients with unruptured intracranial aneurysms treated with flow-diverter devices in the Department of Neurointervention, Department of Neurology, the First Medical Center of Chinese People's Liberation Army General Hospital from January 2020 to January 2024 were retrospectively analyzed. There were 63 males and 111 females, with an age of (53.9±11.4) years (range:23 to 76 years).The occurrence, development and outcome of perioperative complications and related adverse events during treatment were collected and analyzed. The degree of aneurysm embolization was evaluated using the O'Kelly-Marotta (OKM) grading system,with OKM grade C and D as successful occlusion. Results: A total of 187 flow-diverter devices (from 7 different brands) were implanted in 174 patients (with 294 aneurysms). Of these, 151 cases involved standalone stent embolization, 26 cases involved stent embolization combined with coil assistance, and 5 cases involved the use of two flow-diverter devices simultaneously. Twenty-nine cases (16.7%,29/174) suffered intraoperative adverse events, including 10 cases of poor stents deployment, 3 cases of stents migration into the aneurysm sac, 1 cases of abnormal guidewire movement, 4 cases of ischemic events. Complications occurred in 10 patients (5.7%, 10/174), and neurological deficits occurred in 5 patients (2.9%, 5/174). A total of 129 patients completed follow-up for more than 12 months after surgery. There were 117 aneurysms with OKM grade D and 22 with OKM grade C, showing a satisfactory healing rate of 77.7% (139/179). Conclusion: The effect of flow-diverter devices in the treatment of intracranial aneurysms is satisfactory, but complications and adverse events cannot be ignored, especially the relatively high incidence of perioperative adverse events, which requires neurointerventional physicians to be vigilant.

Midterm and long-term angiographic outcomes and efficacy analysis of the Pipeline Embolization Device in the treatment of intracranial aneurysms

Objective: To investigate the midterm and long-term efficacy of flow-diverter device in treating intracranial aneurysms (IAs) and analyze its clinical outcomes in anterior circulation aneurysms and posterior circulation aneurysms. Methods: This is a retrospective case series study. The data of 566 intracranial aneurysm patients (681 aneurysms) treated with the flow-diverter device at Department of Neurosurgery, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University from January 2018 to January 2021 were retrospectively analyzed. There were 205 males and 361 females, with an age (M(IQR)) of 55 (14) years (range:18 to 77 years). Twelve patients (12 aneurysms) had ruptured aneurysms before surgery, and 75 patients (172 aneurysms) had multiple aneurysms. Preoperative modified Rankin scale (mRS) >2 points in 16 patients.There were 444 patients (552 aneurysms) in the anterior circulation group and 122 patients (129 aneurysms) in the posterior circulation group. Postoperative follow-up was conducted via outpatient visits or telephone calls at 3 to 12 months after the procedure. Baseline aneurysm parameters, surgical information, and imaging and clinical outcomes were collected. Univariate and multivariate Logistic regression analyses were used to identify independent factors associated with long-term incomplete aneurysm occlusion. Results: Intraoperative use of flow diverter-assisted coil embolization was performed in 221 patients (226 aneurysms), and balloon assistance was used in 20 patients (22 aneurysms).The intraoperative rupture rate was 0.5% (3/566), and the intraoperative thrombosis rate was 0.7% (4/566). The in-hospital mortality rate was 1.2% (7/566). Postoperative complications included subarachnoid hemorrhage in 5 patients (0.9%), intracerebral hemorrhage in 2 patients (0.4%), ischemic stroke in 19 patients (3.6%), and transient ischemic attack in 16 patients (3.0%). Imaging follow-up was available for 447 patients (548 aneurysms) with a follow-up duration of (16.7±6.7) months (range:3 to 45 months). Incomplete aneurysm occlusion occurred in 79 patients (95 aneurysms), accounting for 17.3% (95/548). Parent artery stenosis was observed in 63 patients (72 aneurysms), accounting for 13.1% (72/548). Clinical follow-up was available for 530 patients (644 aneurysms) with a follow-up duration of (29.4±11.3) months (range:3 to 54 months). One case of mRS score >2 points was observed in 18 patients, accounting for 3.4% (18/530). Among them, the rate of incomplete occlusion in the anterior and posterior circulation group was 16.9% (76/450) and 19.4% (19/98), respectively, and the rate of parent artery stenosis was 10.9% (49/450) and 23.5% (23/98), respectively; the rate of mRS score>2 points was 2.4% (10/415) and 7.0% (8/115), respectively. Univariate and multivariate Logistic regression analysis showed that aneurysm neck size (β=0.075,OR=1.08, P=0.028) and coil use (β=-1.070, OR=0.034, P=0.001) were independent factors influencing long-term aneurysm occlusion. Conclusions: The flow-diverter device demonstrates good safety and efficacy in the midterm and long-term treatment of overall IAs. However, further research is needed to focus on the midterm and long-term treatment outcomes of aneurysms with relatively wide neck and posterior circulation aneurysms.

Treatment of Ruptured Intracranial Aneurysms with Parent Artery Flow Diverter Devices: A Comprehensive Systematic Review and Meta-Analysis.

Surgical clipping and endovascular coiling are well-established treatments for acutely ruptured intracranial aneurysms leading to acute subarachnoid hemorrhage (aSAH). However, these modalities have limitations, particularly in cases involving wide-necked, bifurcating, or dissecting aneurysms. Flow diverter (FD) devices, initially used for unruptured aneurysms, have emerged as an alternative treatment for ruptured aneurysms despite concerns about hemorrhagic complications. This study aimed to perform a comprehensive systematic review and meta-analysis to assess the efficacy and safety of parental artery FD devices in treating ruptured intracranial aneurysms. A systematic search was conducted in Medline, Embase, and Cochrane databases from inception to July 2024. The inclusion criteria focused on studies involving patients with acutely ruptured aneurysms treated with parental artery FDs, with or without adjunctive coiling. Studies were required to report clear, stratified data specific to the population of interest, and include more than five patients. Exclusion criteria included studies on non-ruptured aneurysms, intrasacular flow diversion devices, or previously clipped aneurysms treated with FD. Data extraction was performed independently by two authors, and statistical analysis included single proportion analysis with 95% confidence intervals under a random-effects model, using R Studio. The primary outcome was the rate of aneurysm occlusion at follow-up. Sixty studies encompassing 1300 patients were included. The primary outcome analysis revealed a 90% (95% CI: 87% - 92%; I2= 51%) rate of total occlusion at follow-up. Subgroup analysis indicated an occlusion rate of 89% for anterior circulation aneurysms and 96% for posterior circulation aneurysms. Intraoperative complications occurred in 6% of cases, while postoperative complications were observed in 13%. Rebleeding rates were low at 1%, with a 2% need for retreatment. Good functional outcomes (mRS ≤ 2) were achieved in 82% of patients, and the overall mortality rate was 4%. FD devices demonstrated high rates of aneurysm occlusion and favorable functional outcomes in patients with acutely ruptured intracranial aneurysms. However, the low mortality rate and favorable outcomes observed may reflect selection bias toward patients with less severe SAH. Despite a modest complication rate, the overall safety and efficacy of FD devices suggest they may be a viable alternative to traditional treatments for specific aneurysm types. Further studies, including a broader spectrum of SAH severities, are warranted to optimize their use in clinical practice.

Modeling Fibrin Accumulation on Flow-Diverting Devices for Intracranial Aneurysms.

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 invitro 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 invitro 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.

Flow Diversion for the Management of Posterior Circulation's Intracranial Aneurysms.

The endovascular treatment of posterior circulation aneurysms, although challenging, has been well-established due to various factors that limit the surgical approach in most cases. Flow diversion has also been utilized in the treatment of such aneurysms, although its effectiveness and safety still require evaluation. Numerous studies have examined the outcomes and complication rates in patients treated with FD, resulting in varying findings. This review aimed to summarize the most recent literature concerning the effectiveness of flow diversion devices in posterior circulation aneurysms. Additionally, it highlights reports that compare results in the posterior versus anterior circulation, as well as flow diversion versus stent-assisted coiling.

Flow Diversion for Intracranial Aneurysms With Incorporated Branch: A Subanalysis From the SEASE International Registry

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.

Predictive value of the systemic immune-inflammation index for periprocedural complications in flow diverter treatment for patients with intracranial aneurysms.

Flow-diverter devices (FDs) are effective in treating intracranial aneurysms (IAs) but carry substantial periprocedural risks, particularly ischemic complications. This study aimed to determine if elevated Systemic Immune-Inflammation Index (SII) can independently predict these risks and assess the impact of age and dual antiplatelet therapy on this association. We conducted a retrospective analysis of patients treated with FDs between February 2016 and August 2023, using blood samples taken within six days before surgery to calculate SII. Logistic regression and decision tree analyses assessed the link between SII and periprocedural complications, with subgroups exploring influencing factors. Multivariable analysis identified high SII as an independent predictor of periprocedural complications (OR = 5.306, 95% CI: 1.367-18.455; P = 0.009). The decision tree model confirmed SII > 0.437 as a critical threshold. Subgroup analysis showed a pronounced association of SII with periprocedural complications in patients ≥ 65 years (OR = 36.979, 95% CI: 2.103-650.134; P = 0.014) and in those on clopidogrel plus aspirin therapy (OR = 16.921, 95% CI: 2.733-104.746; P = 0.002). An elevated Systemic Immune-Inflammation Index (SII) > 0.437 significantly correlates with increased periprocedural complications (6.5% vs. 1.8%, P = 0.017). Although not statistically significant, higher SII is associated with a greater rate of ischemic events (3.9% vs. 0.9%). Elevated preoperative SII independently predicts periprocedural complications, particularly ischemic events, in patients undergoing FDs treatment for intracranial aneurysms. This association is particularly pronounced in older patients (> 65 years) and those receiving dual therapy with clopidogrel plus aspirin. Trial Registration: ClinicalTrials.gov (NCT06446778). Registered on May 22, 2024.

Safety and efficacy of flow diverter stents in the treatment of bifurcation cerebral aneurysms: single-center experience.

The use of flow diverter (FD) stents is continually expanding. Aneurysms on arterial bifurcation typically have an undesirable anatomical form, are frequently wide-necked, and include one or more side-branch arteries. In recent years, the off-label use of flow diversion in treating intracranial aneurysms beyond the internal carotid artery has become increasingly popular. This study reports our center's initial experience treating bifurcation aneurysms with FD devices, documenting occlusion outcomes using the O'Kelly-Marotta and modified Cekirge-Saatci scales, as well as the safety of FD usage in bifurcation locations. This retrospective, single-center study analyzed a prospectively maintained database of patients with cerebral aneurysms treated endovascularly. The study identified bifurcation aneurysms that were treated between January 2019 and May 2022 by placing an FD device covering the neck of the aneurysm. Our short series suggests that flow diversion is a viable therapeutic option for bifurcation aneurysms with favorable angiographic outcomes. In highly selective cases, flow diversion may be considered for treating bifurcation aneurysms in patients who will undergo follow-up examinations in the future. Flow diversion has emerged as a valuable technique in the management of bifurcation aneurysms, offering the potential for satisfactory occlusion and long-term outcomes.

Mechanical thrombectomy for internal carotid artery occlusion beyond a large paraclinoid aneurysm

BackgroundWith the launch of mechanical thrombectomy (MT), the prognosis of patients with cerebral infarction associated with large-vessel occlusion has improved. However, good outcomes are still not achieved in a few patients because of technical difficulties.Case presentationA 79-year-old Japanese woman was admitted with sudden-onset left hemiplegia. Tissue plasminogen activator was administered and MT was performed for internal carotid artery occlusion distal to a large paraclinoid aneurysm. Some technical difficulties were unique, including contrast agent retention, difficulty in guiding the system, and avoidance of rupture of the aneurysm. Here, we discuss the technical issues and solutions of the MT procedure employed in this case.ConclusionsThe procedure used in flow-diverter devices should be referenced and a stent-retrieving into an aspiration catheter with proximal balloon technique may be the most appropriate method.

Treatment of intracranial aneurysms using the Tubridge flow diverter.

The Tubridge flow diverter (TFD) was recently developed to treat intracranial aneurysm (IA). In this study, we aimed to assess the safety and efficacy of this novel device. A retrospective cohort of consecutive patients with IA was recruited between June 2017 and February 2022. The studied outcomes were perioperative complications, clinical quality of life, and angiographic IA occlusion. Multivariate logistic regression was performed to explore the potential predictors of perioperative stroke events and IA occlusion. A comprehensive literature review was conducted across five databases for evidence synthesis. Among the patients with IA in our cohort, 144 underwent successful TFD implantation. Postoperative stroke was observed in 11 (7.6%) patients, and 130 (90.3%) patients were discharged with modified Rankin scales (mRS) of ≤2. In the last clinical follow-up (mean, 16.9months), 96.6% of the patients reported a satisfactory quality of life (mRS ≤2). IA occlusion was observed in 84.6% of the patients at the last angiographic follow-up (mean, 10.4months). Aneurysmal subarachnoid hemorrhage [odds ratio (OR), 6.98; 95% confidence interval (CI), 1.11-43.91] and giant IA (OR, 5.63; 95% CI, 1.15-27.48) were associated with perioperative stroke events. The evidence synthesis found high rates of satisfactory quality of life (rate, 98.8%; 95% CI, 97.1-99.9%) and IA obliteration (rate, 78.5%; 95% CI, 74.0-82.7%) after TFD treatment. The pooled complication rate was 13.6% (95% CI, 10.9-16.5%). This study identified a high rate of IA occlusion in patients who received TFD treatment. These patients also reported a satisfactory quality of life. Further studies in larger prospective cohorts with longer follow-up periods are warranted to verify our findings. Key message What is already known on this topic Flow diverter (FD) devices are an optimal tool to modify hemodynamics and treat intracranial aneurysms (IAs). However, the safety and efficacy of a novel self-expanding FD, namely the Tubridge flow diverter (TFD), remain to be fully established owing to the short-term follow-up periods and limited sample size of existing studies. What this study adds In our cohort of patients who received TFD treatment, 96.6% of patients reported satisfactory quality of life at the last clinical follow-up (mean, 16.9months); and 84.6% of IAs were successfully occluded at the last angiographic follow-up (mean, 10.4months). Our comprehensive review and evidence synthesis of existing studies on TFD found high rates of satisfactory quality of life (98.8%; 97.1-99.9%) and IA obliteration (78.5%; 74.0-82.7%). How this study might affect research, practice or policy TFD demonstrated satisfactory performance in the treatment of IAs in our cohort. Studies with larger prospective cohorts and longer follow-up periods are warranted to further investigate this promising novel approach.

Comparative analysis of characteristics, management and clinical outcome of blood blister-like aneurysms treated with flow diverter devices: a systematic review and meta-analysis of 30 studies.

Because of relatively little data for blood blister-like aneurysms (BBAs) treated with flow diverter (FD) devices, existing studies failed to provide comprehensive analysis for the characteristics, management, clinical outcome of the disease. Therefore, we collected and analyzed current evidence aiming to provide quantitatively pooled results for the management, complication, clinical and angiographic outcomes as well as the risk factors of prognosis of BBAs treated with FD devices. A systematic search of PubMed, SCOPUS, Cochrane Library and Web of Science up to May 1, 2024 was conducted for relevant studies. The primary outcomes were to expound the management, characteristics and clinical outcomes of BBAs treated with FD devices. The secondary outcomes were to determine the difference of characteristics and outcomes, as well as risk factors of BBAs treated with FD devices. Two reviewers assessed trial quality and extracted the data independently. All statistical analyses were performed using the standard statistical procedures provided in Review Manager 5.2 and Stata 12.0. A total of 30 reports with 311 of 783 BBA patients were identified. The pooled results indicated that 76.3% BBAs located in internal carotid artery (ICA) and 85% and 84% patients experienced complete occlusion and modified Rankin scale (mRS) score 0-2 respectively at follow-up time. Female BBAs patients (69.9%) were more prevalent and 88.5% patients experienced a favorable outcome at discharge. The overall and periprocedural complications account for 16.8% and 9.1% respectively. The pooled results showed that the incidence of complete occlusion was 50% (95% CI: 31%－69%), 80% (95% CI: 67%－92%) and 84% (95% CI: 77%－91%) at immediate, short and longterm angiographic results respectively. In addition, the favorable, moderate and poor clinical outcomes evaluated with mRS were 89% (95% CI: 85%－94%), 13% (95% CI: 5%－21%), and 8% (95% CI: 3%－13%) respectively. We found that compared to moderate or poor outcomes, patients with good outcomes experienced significantly lower preoperative scores (MD -1.24; 95% CI -1.94－-0.53), more complete occlusion (OR 5.17; 95% CI 1.26－21.15) and less complications (OR 0.20; 95% CI 0.08－0.47) respectively. It was observed that patients experienced a complication had higher onset Hunt-Hess scale (MD 0.49; 95% CI 0.03－0.96) and Fisher's score (MD 1.43; 95% CI 0.72－2.13) respectively. Patients with good outcomes experienced younger age (MD -5.76 years; 95% CI -11.31－-0.21) and lower onset Hunt-Hess scale (MD -0.96; 95% CI -1.45－-0.47) respectively. BBA was middle-aged female predominant and common in ICA. The majority of patients generally experienced favorable outcome with low incidence of periprocedural complications. In addition, good outcomes benefited from lower preoperative scores, more complete occlusion, less complications and younger age. Higher onset Hunt-Hess scale and Fisher's score may increase the risk of complications. Future studies with enough sample size and long follow-up are required to clear the management, long-term outcome and risk factors of BBAs.

Study the local metabolic changes of aneurysms through microcatheter sampling

Intracranial aneurysm is the primary cause of nontraumatic subarachnoid hemorrhage. To assess aneurysm metabolism, we present a method of intra-operatively collecting blood samples from the aneurysm neck, as well as the proximal and distal responsible vessels, using microcatheters. Through these paired comparisons, we can eliminate the interpatient variation usually observed in plasma samples taken from the peripheral vein. We utilized 39 plasma samples from 13 intracranial patients to characterize the metabolite profiles using untargeted liquid chromatography-mass spectrometry. Our findings revealed that l-tyrosine is upregulated at relatively high levels at the aneurysm neck than the proximal and distal aneurysm, whereas phenylpyruvic acid, l-cystine, and l-ornithine are downregulated. Based on this, there was also a significant decrease in arginine within small aneurysm of the internal carotid artery. The 6-month follow-up indicated that patients who experienced good recovery had lower levels of biliverdin, bilirubin, and metabolites of coenzyme Q within the aneurysm. In conclusion, our investigation provides a comprehensive overview of plasma metabolites in patients with intracranial aneurysms, shedding light on potential pathogenetic mechanisms in unruptured intracranial aneurysms. Moreover, the study proposes innovative ideas for establishing postoperative follow-up timelines for flow diverter devices.

Computer Aided Intracranial Aneurysm Treatment Based on 2D/3D Mapping, Virtual Deployment and Online Distal Marker Detection.

To introduce a computational tool for peri-interventional intracranial aneurysm treatment guidance that maps preoperative planning information from simulation onto real-time X-Ray imaging. Preoperatively, multiple flow diverter (FD) devices are simulated based on the 3D mesh of the vessel to treat, to choose the optimal size and location. In the peri-operative stage, this 3D information is aligned and mapped to the continuous 2D-X-Ray scan feed from the operating room. The current flow diverter position in the 3D model is estimated by automatically detecting the distal FD marker locations and mapping them to the treated vessel. This allows to visually assess the possible outcome of releasing the device at the current position, and compare it with the one chosen pre-operatively. The full pipeline was validated using retrospectively collected biplane images from four different patients (5 3D-DSA datasets in total). The distal FD marker detector obtained an average F1-score of 0.67 ( ) in 412 2D-X-Ray scans. After aligning 3D-DSA + 2D-X-Ray datasets, the average difference between simulated and deployed positions was 0.832 mm ( mm). Finally, we qualitatively show that the proposed approach is able to display the current location of the FD compared to their pre-operatively planned position. The proposed method allows to support the FD deployment procedure by merging and presenting preoperative simulation information to the interventionists, aiding them to make more accurate and less risky decisions.

Clinical Outcome of Pipeline Embolization Device with and without Coil to Treat Intracranial Aneurysm: A Systematic Review and Meta-Analysis.

The use of a Pipeline Embolization Device (PED) in combination with coils (PEDC) to treat intracranial aneurysms remains unclear as to whether it offers significant benefits for the patients since the results have varied. This study aimed to investigate the clinical outcome of PEDC compared to PED in treating intracranial aneurysms. We systematically searched the articles from PubMed, Web of Science, and the Cochrane Library databases published before January 25, 2024. We selected studies comparing PEDC vs. PED to treat intracranial aneurysms. Patients treated with PEDC but using dense coiling were excluded from the study. The clinical outcomes observed in this meta-analysis were intraprocedural complications, postoperative complications (stenosis, stroke, hemorrhage, mortality), favorable outcome (mRS ≤ 2), complete occlusion rate, and retreatment rate. Forest plot was used to analyze pooled Odds Ratio (OR) of clinical outcomes. A total of 3001 subjects from nine observational studies were included. PEDC was mainly used to treat larger aneurysms. PEDC has a significantly higher complete occlusion rate at 6 months [OR= 2.66, 95% CI(1.26, 5.59), p= 0.01], a lower retreatment rate [OR= 0.18, 95% CI(0.05, 0.07), p= 0.010], higher stroke-related complications [OR= 1.66, 95% CI(1.16, 2.37), p= 0.005], and higher hemorrhage-related complications [OR= 1.98, 95% CI(1.22, 3.21), p = 0.005]. There was no significant difference in intraprocedural complications, stenosis-related complications, mortality, favorable outcomes, and complete occlusion at the end of the study. No randomized controlled trials have been performed comparing PEDC and PED. Considering that all the included studies were observational, the patients' baseline characteristics were not completely balanced. This meta-analysis study showed that PEDC in large intracranial aneurysms induces a faster complete occlusion rate at 6 months and a lower retreatment rate. However, it increases the risk of stroke-related postoperative complications, and the faster complete aneurysm occlusion rate found in this study did not correlate with a reduction in long-term aneurysm or distal artery ruptures. Thus, this study suggests the need to find a better strategy to improve long-term hemorrhage-related complications in large intracranial aneurysms. F = female; FDDs = flow-diverter devices; M = male; NOS = Newcastle-Ottawa Scale; PED = pipeline embolization device; PEDC = pipeline embolization device in combination with coils.

Current state of endovascular treatment of anterior cerebral artery aneurysms.

The locations of anterior cerebral artery (ACA) aneurysms vary, and various aneurysms can occur along the course of the ACA. Ruptured and some unruptured ACA aneurysms may require aggressive treatment to avoid bleeding or rebleeding. Although open surgery is an effective treatment for ACA aneurysms, endovascular treatment (EVT) is becoming an alternative treatment in select cases. EVT techniques for ACA aneurysms often vary and are performed on a case-by-case basis according to the nature and location of the aneurysm. To better understand the EVT strategy for ACA aneurysms, it is necessary to review EVT for ACA aneurysms. In this review, the following topics are discussed: ACA anatomy and anomalies, classifications of ACA aneurysms, the natural history of ACA aneurysms, open surgery and EVT statuses for ACA aneurysms, EVT techniques for various ACA aneurysms, and the prognosis and complications of EVT for ACA aneurysms. According to our review and experience, traditional coiling EVT is still the preferred therapy for most ACA aneurysms. For A1 aneurysms, EVT is challenging. After the selection of appropriate cases, deployment of a flow diverter and Woven EndoBridge device can result in a good prognosis for patients with ACA aneurysms. In addition, parent artery occlusion can be used to treat A1 aneurysms with good collateral circulation and some distal ACA aneurysms. In general, EVT is gaining popularity as an alternative treatment option for ACA aneurysms.

Pipeline versus non-pipeline flow diverter treatment for M1 aneurysms: A systematic review and meta-analysis.

The flow diversion treatment of aneurysms located distal to the Circle of Willis has recently increased in frequency. We conducted a systematic review and meta-analysis of the clinical and radiological outcomes of flow diverter (FD) embolization in treating M1 aneurysms. PubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched up to May 2024 using the Nested Knowledge platform. We included studies assessing the long-term clinical and radiological outcomes for M1 aneurysms. Results of FDs classified as Pipeline Embolization Devices (PED) versus other types of FDs. Angiographic occlusion rates, ischemic and hemorrhagic complications, and favorable clinic outcomes were included. All data were analyzed using R software version 4.2.2. Thirteen studies with 112 total patients (58 patients for PED and 54 patients for other FD devices) were included in our meta-analysis. The overall adequate (complete + near-complete) occlusion rates were 85.1%. The complete occlusion rate was higher with PED than with other FD devices (72.9% PED and 41.6% for non-PED FDs, respectively, p-value <.01). The ischemic complications were 9.9% and 9.0% for the PED and non-PED groups, respectively (p-value = .89). The overall modified Rankin Scale 0-2 was 100% for the non-PED and 97.1% for the PED group (p-value = .51). In-stent stenosis rate was 7.5% for PED devices compared to 2.6% in the non-PED group (p-value = .35). This relatively small meta-analysis showed high rates of adequate and complete occlusion in FD treatment of M1 segment aneurysms, with favorable safety profiles. PEDs were associated with higher rates of complete aneurysm occlusion compared to other types of FDs.

Comparative Efficacy of Flow Diverter Devices in the Treatment of Carotid Sidewall Intracranial Aneurysms: aRetrospective, Multicenter Study.

The comparative efficacy and safety of first-generation flow diverters (FDs), Pipeline Embolization Device (PED) (Medtronic, Irvine, California), Silk (Balt Extrusion, Montmorency, France), Flow Re-direction Endoluminal Device (FRED) (Microvention, Tustin, California), and Surpass Streamline (Stryker Neurovascular, Fremont, California), is not directly established and largely inferred. This study aimed to compare the efficacy of different FDs in treating sidewall ICA intracranial aneurysms. We conducted aretrospective review of prospectively maintained databases from eighteen academic institutions from 2009-2016, comprising 444 patients treated with one of four devices for sidewall ICA aneurysms. Data on demographics, aneurysm characteristics, treatment outcomes, and complications were analyzed. Angiographic and clinical outcomes were assessed using various imaging modalities and modified Rankin Scale (mRS). Propensity score weighting was employed to balance confounding variables. The data analysis used Kaplan-Meier curves, logistic regression, and Cox proportional-hazards regression. While there were no significant differences in retreatment rates, functional outcomes (mRS 0-1), and thromboembolic complications between the four devices, the probability of achieving adequate occlusion at the last follow-up was highest in Surpass device (HR: 4.59; CI: 2.75-7.66, p < 0.001), followed by FRED (HR: 2.23; CI: 1.44-3.46, p < 0.001), PED (HR: 1.72; CI: 1.10-2.70, p = 0.018), and Silk (HR: 1.0ref. standard). The only hemorrhagic complications were with Surpass (1%). All the first-generation devices achieved good clinical outcomes and retreatment rates in treating ICA sidewall aneurysms. Prospective studies are needed to explore the nuanced differences between these devices in the long term.

Flow Diversion for Endovascular Treatment of Intracranial Aneurysms: Past, Present, and Future Directions.

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.

Comparative meta-analysis of endovascular strategies for intracranial dissecting aneurysms: Flow diverters versus stents with or without coiling.

Intracranial dissecting aneurysms present a challenging subset linked to considerable morbidity and mortality, necessitating effective therapeutic strategies to prevent complications. Traditional treatments face technical limitations, while emerging endovascular modalities like stent-assisted coiling, multiple stenting, and flow-diverting devices (FDDs) offer promise in reducing periprocedural risks and enhancing patient outcomes. The aim of this study is to compare the safety and efficacy outcomes of endovascular treatment for intracranial dissecting aneurysms using FDDs versus stents (with or without coiling). A systematic review and meta-analysis were conducted following established guidelines. The search included PubMed, Scopus, Web of Science, and Embase databases up to July 30, 2023. Eligible studies reporting outcomes of interest in both FDD and stent-treated groups were included, and the data was extracted and analyzed using STATA software. Six studies were analyzed, involving 131 patients in the FDD group and 199 patients in the stent group. The pooled rates for favorable functional outcomes (86.8% vs. 86%), mortality (3.9% vs. 6%), adequate occlusion (79.7% vs. 86.3%), aneurysm recurrence (1.3% vs. 13.3%), in-stent stenosis/thrombosis (7% vs. 6.9%), ischemic events/infarctions (6.7% vs. 7.8%), retreatment (7% vs. 8.6%), and technical success (100% vs. 98.7%) were comparable in individuals treated with FDDs and stents (p > 0.05 in all cases). Additionally, complete occlusion rates were not significantly different between FDD (62.7%) and stent-treated patients (75.2%) (p = 0.06). However, after excluding one study in a leave-one-out analysis of the random effects meta-analysis, a significant difference in the pooled rates of this outcome was observed between the FDD (59.2%) and stent (75.2%) groups (p = 0.034). FDDs present a promising approach for the treatment of intracranial dissecting aneurysms, yielding outcomes that are roughly comparable to stent-based methods. However, the absence of randomized trials and data limitations highlight the need for further research to enhance treatment strategies.

Multiple telescopic stenting versus single flow diverter for the treatment of vertebral artery dissecting aneurysm.

Reconstruction methods, including stent-assisted coiling, multiple telescopic stents, and flow diverters, are preferred modalities for the treatment of unruptured vertebral artery dissecting aneurysms (VADAs). We aimed to compare the clinical outcomes between two reconstructive flow diversion techniques: single flow diverter (FD) device and multiple telescopic stenting (TS). We retrospectively reviewed the clinical data of 39 patients with unruptured VADAs. Of these, 17 patients were treated with multiple TS and 22 with a single FD device. Aneurysm characteristics and clinical outcomes were compared between the two groups. All aneurysms included in this study successfully achieved flow diversion, regardless of the treatment modality and duration. However, the mean procedure duration to complete the diversion was shorter in the FD group. Subgroup analysis in TS group showed that there were no significant clinical differences between the low-profile visualized intraluminal support and Enterprise stents, except for the mean procedure duration. Both the single FD and multiple TS methods showed excellent angiographic and clinical outcomes in the treatment of unruptured VADAs. However, single FD required a shorter procedure duration and was associated with faster achievement of complete flow diversion.