Flow diversion of fusiform intracranial aneurysms

Flow diversion for posterior circulation intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND

Posterior circulation (PC) aneurysms are associated with a higher risk of rupture. Flow diverters (FDs) are widely used for carotid intracranial aneurysms, but their role in PC aneurysms is less established. This meta-analysis examines the available literature on the safety and effectiveness of FDs for PC aneurysms.

METHOD

We conducted a systematic search from database inception until October 2024. The primary effectiveness outcome was complete occlusion rate defined by the Raymond-Roy and/or O'Kelly-Marotta scales. Primary safety outcomes included thromboembolic event rates following implantation. Secondary outcomes included procedure-related mortality, good functional outcome (GFO), and retreatment. Pool estimates were calculated using a random-effect model. Subgroup analysis based on morphology and study design was also conducted.

RESULTS

A total of 42 studies met our inclusion criteria. A total of 1698 patients were treated with FDs for 1760 PC aneurysms. Among these cases, 47.6% were in the vertebral artery. Our pooled overall analysis of complete occlusion rates was 72.73% (P<0.0001; I2=67.2%), and the pooled thromboembolic events rate following implantation was 11.70% (P<0.0046; I2=70.5%). Additionally, the pooled mortality rate was 8.07% (P<0.0001; I2=61.5%), the retreatment rate was 6.59% (P<0.4260; I2=1%), and the pooled GFO rate was 83.99% (P<0.0001; I2=76%). Subgroup analysis revealed that fusiform-dolichoectatic had a complete occlusion rate of 48.29% (P<0.3223; I2=11.7%).

CONCLUSION

FDs for PC aneurysms achieve generally adequate occlusion rates, except in dolichoectatic-fusiform subtypes. Despite achieving adequate occlusion rates, FD use was associated with higher thromboembolic events, mortality, and retreatment rates, which necessitates careful patient selection.

Comparative analysis of safety and efficacy of flow diversion with and without surface modification technology, FRED-X, FRED, PED shield and PED in 386 patients: A single center experience with systematic review and network meta analysis

INTRODUCTION

The FRED-X is a newer generation flow diverting stent (FDS) with surface modification that has demonstrated favorable efficacy in treating intracranial aneurysms. Our study provides an analysis of patients treated using FRED-X compared to FRED, PED Shield and PED.

MATERIALS AND METHODS

This was a retrospective single center study and a systematic review with network meta analysis of patients who underwent flow diversion using FRED-X, FRED, PED Shield or PED. Multivariate logistic regression was used to assess long-term outcomes of interest- angiographic occlusion, in-stent stenosis and functional outcome at 6- and 12-month follow up.

RESULTS

386 patients with 386 aneurysms were included. The average age of the cohort was 56.2 years, and 81 % was female. PED had significantly higher aneurysm occlusion rates compared to FRED-X at 6- and 12-months (OR: 3.03, 95 % CI: 1.36-6.62 and OR: 4.01, 95 % CI: 1.26-12.2), with higher odds of absent in-stent stenosis (OR: 9.03, 95 % CI: 3.63-23.3 and OR: 9.58, 95 % CI: 2.56-33.8) at 6- and 12-months, respectively. Rates of stroke, TIA, ICH and mortality were not significantly different across cohorts. All patients were functionally independent on follow-up. A network meta-analysis revealed no significant difference in occlusion rates among each of the included FDS.

CONCLUSION

Our study revealed comparable 12-month occlusion rates and in-stent stenosis between surface modified devices, FRED-X and PED Shield. In addition, angiographic results were comparable between FRED-X and the first generation FRED, however classic PED demonstrated higher rates of angiographic occlusion with lower in-stent stenosis.

Statins may Decrease Aneurysm wall Enhancement of Unruptured Fusiform Intracranial Aneurysms: A high-resolution 3T MRI Study

Inflammation plays an integral role in the formation, growth, and progression to rupture of unruptured intracranial aneurysms. Aneurysm wall enhancement (AWE) in high-resolution magnetic resonance imaging (HR-MRI) has emerged as a surrogate biomarker of vessel wall inflammation and unruptured intracranial aneurysm instability. We investigated the correlation between anti-inflammatory drug use and three-dimensional AWE of fusiform intracranial aneurysms (FIAs). We retrospectively analyzed consecutive patients with FIAs in our database who underwent 3T HR-MRI at three Chinese centers. FIAs were classified as fusiform-type, dolichoectatic-type, or transitional-type. AWE was objectively defined using the aneurysm-to-pituitary stalk contrast ratio in three-dimensional space by determining the contrast ratio of the average signal intensity in the aneurysmal wall and pituitary stalk on post-contrast T1-weighted images. Data on aneurysm size, morphology, and location, as well as patient demographics and comorbidities, were collected. Univariate and multivariate logistic regression analyses were performed to determine factors independently associated with AWE of FIAs on HR-MRI. In total, 127 FIAs were included. In multivariate analysis, statin use (β = -0.236, P = 0.007) was the only independent factor significantly associated with decreased AWE. In the analysis of three FIA subtypes, the fusiform and transitional types were significantly associated with statin use (rs = -0.230, P = 0.035; and rs = -0.551, P = 0.010; respectively). It establishes an incidental correlation between the use of statins daily for ≥ 6 months and decreased AWE of FIAs. The findings also indicate that the pathophysiology may differ among the three FIA subtypes.

Open Microsurgical Versus Endovascular Management of Unruptured and Ruptured Brain Aneurysms

Open microsurgical and endovascular techniques are the 2 primary strategies for treating intracranial aneurysms. Microsurgical clipping and adjuvant technical maneuvers are well-established techniques with a track record for high occlusion rates and durable repairs. Endovascular, endosaccular, and extrasaccular therapies are associated with lower peri-procedural morbidity but with generally higher rates of retreatment. We discuss key clinical and anatomic considerations in treatment decision-making and compare the risks and benefits of microsurgical vs endovascular treatment within each context.

Treatment strategies and outcomes for intracranial fusiform aneurysms: A systematic review and meta-analysis

BACKGROUND

Fusiform aneurysms are a distinct subgroup of intracranial aneurysms with unique characteristics and pose a treatment challenge compared to common saccular aneurysms. Traditionally, surgery was the main treatment; however, endovascular techniques are gaining favor.

METHODS

We searched major databases for studies on treatment, clinical outcomes, and radiological outcomes of intracranial fusiform aneurysms published before May 31st, 2023 in order to compare surgical Vs endovascular treatment strategies. Pooled data analysis was performed using a random-effects model.

RESULTS

This systematic review and meta-analysis analyzed 1704 patients with 1737 fusiform aneurysms from 63 studies. Endovascular treatment, particularly stent-assisted coiling and stenting, emerged as the preferred approach with lower mortality and complication rates compared to surgery. Aneurysm location played a role in outcomes, with anterior circulation aneurysms generally faring better. Deconstructive strategies, designed to occlude the parent artery, carried a doubled risk of complications compared to reconstructive approaches, which aim to preserve blood flow (OR: 2.188; 95% CI: 1.474-3.248; p < 0.001).

CONCLUSION

Endovascular techniques are becoming the mainstay of treatment for fusiform aneurysms, offering improved safety and efficacy compared to surgery. Anterior circulation location and reconstructive strategies are associated with better outcomes. However, no significant differences in OR for early complete occlusion were found between surgery and endovascular techniques at discharge and follow-up with very low heterogeneity among studies.

Complex intracranial aneurysms: a DELPHI study to define associated characteristics

PURPOSE

Intracranial aneurysms present significant health risks, as their rupture leads to subarachnoid haemorrhage, which in turn has high morbidity and mortality rates. There are several elements affecting the complexity of an intracranial aneurysm. However, criteria for defining a complex intracranial aneurysm (CIA) in open surgery and endovascular treatment could differ, and actually there is no consensus on the definition of a "complex" aneurysm. This DELPHI study aims to assess consensus on variables defining a CIA.

METHODS

An international panel of 50 members, representing various specialties, was recruited to define CIAs through a three-round Delphi process. The panelists participated in surveys with Likert scale responses and open-ended questions. Consensus criteria were established to determine CIA variables, and statistical analysis evaluated consensus and stability.

RESULTS

In open surgery, CIAs were defined by fusiform or blister-like shape, dissecting aetiology, giant size (≥ 25 mm), broad neck encasing parent arteries, extensive neck surface, wall calcification, intraluminal thrombus, collateral branch from the sac, location (AICA, SCA, basilar), vasospasm context, and planned bypass (EC-IC or IC-IC). For endovascular treatment, CIAs included giant size, very wide neck (dome/neck ratio ≤ 1:1), and collateral branch from the sac.

CONCLUSIONS

The definition of aneurysm complexity varies by treatment modality. Since elements related to complexity differ between open surgery and endovascular treatment, these consensus criteria of CIAs could even guide in selecting the best treatment approach.

Fusiform versus Saccular Intracranial Aneurysms-Hemodynamic Evaluation of the Pre-Aneurysmal, Pathological, and Post-Interventional State

Minimally-invasive therapies are well-established treatment methods for saccular intracranial aneurysms (SIAs). Knowledge concerning fusiform IAs (FIAs) is low, due to their wide and alternating lumen and their infrequent occurrence. However, FIAs carry risks like ischemia and thus require further in-depth investigation. Six patient-specific IAs, comprising three position-identical FIAs and SIAs, with the FIAs showing a non-typical FIA shape, were compared, respectively. For each model, a healthy counterpart and a treated version with a flow diverting stent were created. Eighteen time-dependent simulations were performed to analyze morphological and hemodynamic parameters focusing on the treatment effect (TE). The stent expansion is higher for FIAs than SIAs. For FIAs, the reduction in vorticity is higher (Δ35-75% case 2/3) and the reduction in the oscillatory velocity index is lower (Δ15-68% case 2/3). Velocity is reduced equally for FIAs and SIAs with a TE of 37-60% in FIAs and of 41-72% in SIAs. Time-averaged wall shear stress (TAWSS) is less reduced within FIAs than SIAs (Δ30-105%). Within this study, the positive TE of FDS deployed in FIAs is shown and a similarity in parameters found due to the non-typical FIA shape. Despite the higher stent expansion, velocity and vorticity are equally reduced compared to identically located SIAs.

Cerebral Myxomatous Aneurysms: Case Series and Systematic Review of Literature with Adequate Follow-Up Periods and Aneurysmal Wall Biopsy Results

BACKGROUND

Cerebral myxomatous aneurysms (CMA) are intracranial aneurysms caused by cardiac myxoma. The exact mechanism underlying their development has not yet been elucidated. And an optimal treatment method has not yet been established because of rarity of the disease. In addition, most existing reports have had a short follow-up period or lack of follow-up imaging test results. The aim of this study was to provide better insights into the course and treatment options of CMAs.

METHODS

We describe 4 CMA patients treated in our hospital and literature search was performed using PubMed and Embase databases. Keywords used were as follows: "cerebral myxomatous aneurysm", "myxomatous aneurysm", "cardiac myxoma", and "intracranial aneurysm". Only publications in English and related to this disorder with adequate follow-up periods and aneurysmal wall biopsy results were included. Clinical, radiological, pathological, and treatment characteristics were analyzed.

RESULTS

A total of 149 CMA cases were managed conservatively that included 9 enlargements, 6 regressions, and 134 stable aneurysms, which were identified for a total of 453.33 aneurysm years (1.91% per aneurysm year, 1.27% per aneurysm year, and 28.76% per aneurysm year, respectively). Poor outcome rate was high in cases with hemorrhage (either parenchymal or subarachnoidal hemorrhage) due to rupture of the CMA (46.67%, 7 out of 15). Thirteen cases had aneurysm biopsy results of which 11 showed tumor invasion on the aneurysm wall.

CONCLUSIONS

Even though the natural course of unruptured, benign-looking CMAs appears to be favorable, the presence or absence of viable tumor cells in the aneurysm may promote an unfavorable disease course. In the case of large, symptomatic, and enlarging CMAs, surgical, endovascular, or combined treatment should be considered as the mortality and morbidity due to rupture might be high.

Treatment of fusiform aneurysms with a pipeline embolization device: a multicenter cohort study

BACKGROUND

Intracranial fusiform aneurysms are less common than saccular aneurysms, but are associated with higher mortality and morbidity. We conducted this study to determine the safety and efficacy of the pipeline embolization device (PED) to treat intracranial fusiform aneurysms.

METHODS

This was a multicenter, retrospective, and observational study. Data for this study came from the PLUS study conducted from 2014 to 2019 across 14 centers in China. Univariate and multivariable logistic regression analyses were performed to evaluate predictors of the occlusion rate and complication.

RESULTS

A total of 1171 consecutive patients with 1322 intracranial aneurysms participated in this study. Among the participants, 104 patients with 109 fusiform aneurysms were eligible for this analysis (mean age 49 years, 36.5% women, aneurysm mean size 14.7 mm, 55% in the posterior circulation, and 6% in the basilar artery). Mean follow-up time was 9.0 months (range 3-36 months). The last DSA angiographic follow-up was available for 85 patients, and 58 aneurysms (68.2%) were completely occluded. The overall complication rate and mortality were 17.3% and 2.8%, respectively. Multivariate analysis demonstrated that age (OR=1.007, p=0.037) and cerebral atherosclerosis (OR=1.441, p=0.002) were associated with incomplete occlusion of fusiform aneurysms after PED treatment.

CONCLUSION

PEDs may be an effective treatment for intracranial fusiform aneurysms, with a favorable occlusion rate. However, because these treatments have a relatively high rate of complications, PED treatment for fusiform aneurysms should be carefully and strictly controlled. Our analysis showed that PEDs with adjunctive coiling did not significantly improve the occlusion rate of fusiform aneurysms.

Endovascular Flow Diversion for Hemifacial Spasm Due to an Unruptured Fusiform Vertebral Artery Aneurysm: A Case Report

BACKGROUND AND IMPORTANCE

Hemifacial spasm (HFS) caused by a fusiform aneurysm is rare and difficult to treat. We present the first case of successful endovascular flow diversion treatment for HFS due to a fusiform aneurysm.

CLINICAL PRESENTATION

A 46-year-old man suffered from right HFS for 6 months because of a fusiform right vertebral artery aneurysm compressing the root exit zone of cranial nerve VII. He successfully underwent flow diversion, with immediate disappearance of his HFS. Follow-up digital subtraction angiography 3 months after treatment showed complete resolution of the aneurysm.

CONCLUSION

Flow diversion might be a promising treatment option for HFS due to a fusiform vertebral artery aneurysm.

Results of Double Low-Profile Visualized Intraluminal Support Blue Stenting for the Treatment of Fusiform Cerebral Aneurysms

BACKGROUND

The flow diversion technique is increasingly used for reconstructive endovascular treatment of fusiform cerebral aneurysms. Double stenting with the Low-profile Visualized Intraluminal Support (LVIS) Blue stent is one of the flow diversion techniques. The aim of this study was to analyze the clinical and angiographic outcomes of LVIS Blue double stenting for fusiform cerebral aneurysms.

METHODS

Between March 2016 and July 2020, double LVIS Blue stenting was attempted in 25 fusiform cerebral aneurysms. Patient medical records and radiological images were carefully reviewed.

RESULTS

The technical success rate was 100% (25/25). Six aneurysms (24.0%) were located in the anterior circulation and 19 aneurysms (76.0%) were located in the posterior circulation. Intraprocedural thromboembolic complications occurred in 1 patient (4.0%). During the follow-up period (30.8 ± 14.2 months), there were no deaths or delayed complications. The mean angiographic follow-up duration was 28.2 ± 12.8 months. Follow-up angiography revealed complete obliteration (O'Kelly-Marotta D) in 21 (84.0%) patients and near-complete obliteration (O'Kelly-Marotta C + 2 matched with Kamran-Byrne grade 3) in 2 (8.0%) patients. Two patients (8.0%) showed worsening of obliteration grades. One (4.0%) patient required retreatment. There was no significant in-stent stenosis or branch occlusion covered by stents.

CONCLUSIONS

Double stenting using LVIS Blue stents for the treatment of fusiform cerebral aneurysms is effective and safe.

Effect and safety of Tubridge flow diverter in the treatment of unruptured intracranial aneurysms

The effect and safety of the Tubridge flow diverting device are unknown in the treatment of intracranial aneurysms after optimization of the device, improvement in the deployment of the device, and accumulation of experience of using the device. This retrospective one-center study was performed to investigate the clinical effect and safety of the Tubridge flow diverting device in the treatment of unruptured intracranial aneurysms. Twenty-three patients with 33 unruptured intracranial aneurysms which were treated with the Tubridge device were retrospectively enrolled. The clinical data, endovascular procedure, complications, and follow-up were analyzed. Twenty-seven Tubridge devices were deployed to treat the 33 aneurysms, and the deployment was failed in 1 case, resulting in the success stenting rate of 96.3%. In 5 (15.2%) aneurysms, coils were loosely packed. Peri-procedural complications occurred in 2 patients (8.7%), including 1 procedure-related complication in which the distal end of a Tubridge device herniated into the aneurysm cavity. In another case, weakness of left upper limb occurred on the second day post procedure, with instent thrombosis being suspected, which was recovered after medication. No other complications occurred. Twenty-three (100%) patients had clinical follow-up 6 months later, with the mRS of 0 in 21 patients, 1 in 1, and 2 in 1. Five (21.7%) patients with 11 aneurysms underwent digital subtraction angiography at 6-month follow-up, with 8 aneurysms being completely occluded (Raymond grade I) and 3 aneurysms still visible (Raymond grade III). The Tubridge flow diverter may be safe and effective in the treatment of unruptured intracranial aneurysms with low perioperative complications and good follow-up outcomes even though multi-center and prospective clinical studies with a large size sample are still needed to validate these results.

Multiple Pipeline Embolization Devices for the Treatment of Complex Intracranial Aneurysm: A Multi-Center Study

Background

The Pipeline for Uncoilable or Failed Aneurysms (PUFS) trial primarily demonstrated the safety and efficacy of the implantation of multiple pipeline embolization devices (multi-PEDs) for large/giant intracranial aneurysms. However, no study has focused on when, why, or how to apply multi-PEDs.

Objective

The purpose of this study was to investigate the indications and strategies of using multi-PEDs for complex intracranial aneurysms.

Methods

Patients who had been treated with two or more PEDs were included in the post-market multicenter registry study from 2014 to 2019, across 14 centers in China. Indications, strategies, perioperative safety, and clinical outcomes were retrospectively analyzed. The modified Rankin scale (mRS) score was used to evaluate clinical outcomes comprehensively, and the O’Kelly–Marotta (OKM) grading scale was used to evaluate aneurysm healing results.

Results

A total of 55 intracranial aneurysms were treated with multi-PEDs. There were 20 fusiform aneurysms with a large range, 25 large/giant saccular aneurysms, six aneurysms with failed treatment, and four aneurysms with greatly varied diameters of the parent artery. The strategies included telescope techniques in 40 patients and overlap techniques in 15 patients. In total, 120 stents were deployed in 55 patients. The operation styles included 25 patients (55.6%) with two PEDs, 21 patients (38.2%) with two PEDs combined with coiling, four patients (7.3%) with three PEDs, four patients (7.3%) with three PEDs combined with coiling, and one patient (1.8%) with four PEDs. Angiography revealed OKM D in two, OKM C in seven, and OKM A and B in 46 cases after surgery. During the perioperative period, eight patients developed neurological dysfunction, three of whom died. A total of thirty-four patients were followed up with digital subtraction angiography for 2–45 (8.2 ± 8.0) months. Angiography revealed OKM D in 26, OKM C in five, and OKM B in three. At the last follow-up, the mRS score was 0–1 in 52 patients.

Conclusion

The treatment of anterior circulation aneurysms with multi-PEDs is safe and effective. The implantation of multi-PEDs could be considered for large-scale fusiform aneurysms, large/giant saccular aneurysms with a jet-sign, salvage of failed PED treatments, and in cases where the diameter of the parent artery varies greatly.

Anterior Circulation Fusiform Aneurysms Have a Lower Occlusion Rate After Pipeline Embolization Device Treatment Than Posterior Circulation Fusiform Aneurysms: A Multicenter Cohort Study

Objective:

Intracranial fusiform aneurysms are uncommon and can occur in vessels of the anterior circulation (AC) or posterior circulation (PC). While flow diversion is one treatment option, research into Pipeline Embolization Device (PED) treatment is lacking. This study explored the efficacy and safety of PED treatment for intracranial fusiform aneurysms, and compared therapeutic effects between AC and PC aneurysms.

Methods

In the post-market multi-center cohort study of embolization of intracranial aneurysms with PED in China (PLUS) registry study, we retrospectively analyzed 71 fusiform aneurysms in 67 patients among 1,171 patients treated with a PED from November 2014 to October 2019. The general characteristics, perioperative status, aneurysm occlusion rate at the last follow-up angiography, and changes in modified Rankin Scale scores were analyzed. Aneurysms were divided into AC and PC groups, and univariate and multivariate analyses were conducted.

Results

The study included 26 AC (25 patients) and 45 PC (42 patients) aneurysms. A total of 75 PEDs were used, an average of 1.1 PEDs were used, and the median follow-up was 6.7 months. Fifty aneurysms (71.4%) were occluded and twenty (28.5%) were incompletely occluded. There were significantly more occluded aneurysms in the PC group than in the AC group (12 vs. 38; P = 0.001). Risk factors for incomplete occlusion were AC aneurysms (P = 0.001) and a perforating artery originating from the aneurysm (P = 0.006). The mean modified Rankin Scale score was significantly lower at the last follow up than preoperatively (0.58 vs. 0.21; P = 0.0001).

Conclusion

Non-overlapping PED is a safe and effective treatment for both AC and PC fusiform aneurysms. The occlusion rate of AC fusiform aneurysms is lower than that of PC.

Pipeline embolization of proximal middle cerebral artery aneurysms: A multicenter cohort study

BACKGROUND AND PURPOSE

Flow diversion of aneurysms located in the M1 segment and middle cerebral artery bifurcation with Pipeline embolization device is sometimes performed, but further study is needed to support its regular use in aneurysm treatment. Here, we report measures of safety and efficacy for Pipeline embolization in the proximal middle cerebral artery in a multi-center cohort.

MATERIALS AND METHODS

Clinical and angiographic data of eligible patients were retrospectively obtained from participating centers and assessed for key clinical and angiographic outcomes. Additional details were extracted for patients with complications.

RESULTS

In our multi-center cohort, complete aneurysm occlusion was achieved in 71% (17/24) of treated aneurysms. There were no deaths or disabling strokes, but non-disabling ischemic strokes occurred in 8% (2/24) of patients. For aneurysms in the M1 segment, complete aneurysm occlusion was observed in 75% (12/16) of aneurysms, aneurysm volume reduction was observed in 100% (16/16) of aneurysms, and non-disabling ischemic strokes occurred in 13% (2/16) of patients. For aneurysms at the middle cerebral artery bifurcation, complete aneurysm occlusion was observed in 63% (5/8) of aneurysms, aneurysm volume reduction occurred in 88% (7/8) of aneurysms, and ischemic or hemorrhagic complications occurred in 0% (0/8) of patients.

CONCLUSION

Pipeline embolization of cerebral aneurysms in the M1 segment and middle cerebral artery bifurcation demonstrated a 71% rate of complete aneurysm occlusion. There were no deaths or disabling strokes, but there was an 8% rate of non-disabling ischemic strokes.

Intracranial Fusiform and Circumferential Aneurysms of the Main Trunk: Therapeutic Dilemmas and Prospects

Intracranial fusiform and circumferential aneurysms (IFCAs), especially those located on the main trunk, are uncommon and difficult to manage. Currently, literature focused on IFCAs on the main trunk of cerebral arteries is lacking. The treatment of IFCAs is still under debate. Therefore, in this review, we further explore the treatment of this complicated entity. In addition, we also present some interesting cases. Based on the literature review and our experience, we found that IFCAs are often located in the vertebrobasilar system and that ruptured or large symptomatic IFCAs are associated with increased mortality and higher rebleeding rates. The treatment strategies for IFCAs can be classified as deconstructive and reconstructive methods via open surgery and/or endovascular treatment (EVT). Currently, EVT is a popular method and the main therapeutic choice. In particular, flow diversion has revolutionized the treatment of IFCAs. Parent artery occlusion (PAO) with or without revascularization may still be considered a suitable choice. Complex IFCAs that cannot be resolved by EVT can also be treated via open surgery with or without extracranial–intracranial bypass. Targeted embolization for the weak points of IFCAs is a temporary or palliative choice that is rarely used. In summary, despite complications, both surgical treatment and EVT are effective options for appropriately selected cases. Due to the development of endovascular implants, EVT will have better prospects in the future.