Coil embolization of intracranial saccular aneurysms using the Low-profile Visualized Intraluminal Support (LVIS™) device

Comparative Analysis of the Low-Profile Acclino Stent and the Enterprise Stent for the Treatment of Unruptured Intracranial Aneurysms

OBJECTIVE

In preliminary studies, advanced intracranial stents appear to have a favorable safety profile for intracranial aneurysm treatment. This dual-center study is a head-to-head comparison of the low-profile Acandis Acclino stent (a third-generation stent) and the first- and second-generation Enterprise stent.

METHODS

Patients who underwent stent-assisted coiling with either the Enterprise or the Acclino stent for unruptured aneurysms during an 8-year period were enrolled and compared for complications, clinical outcomes, and angiographic results. Primary outcome measures were ischemic stroke rate and mid-term complete occlusion rate. Propensity score adjustment was performed to account for small differences between the groups.

RESULTS

Enterprise and Acclino stents were used in 48 cases each. The overall rate of thrombotic complications was higher in the Enterprise group than in the Acclino group (20.8% vs. 4.2%, HR: 6.6, 95%CI: 2.2-20.0, P = 0.01, adjusted P < 0.01), which translated into a higher rate of major ischemic stroke after Enterprise treatment (6.3% vs. 0%, HR: 2.1, 95%CI: 1.8-2.4, P = 0.08, adjusted P < 0.01). Mid-term and long-term angiographic follow-up showed complete occlusion rates of 83.3% and 75.0% for Enterprise and 89.2% and 75.9% for Acclino (both P > 0.05). Retreatment rates were 10.4% in the Enterprise group and 4.2% in the Acclino group (P = 0.42, adjusted P = 0.10).

CONCLUSIONS

The results indicate a favorable safety profile of the Acclino over the Enterprise, justifying the use of advanced stent systems in clinical practice. However, further comparative studies of the Acclino and other competing stent systems are needed to draw a definitive conclusion on the state of stent-assisted coiling.

A Novel Braided Stent With Customized Simulation Software for Treatment of Intracranial Aneurysms: Multicenter Prospective Trial Before Unrestricted Clinical Application

BACKGROUND AND OBJECTIVES

Planning/guidance software became important tools for physicians' presurgical optimal decision-making. However, there are no intracranial stent products with specifically associated simulation software. We report the "premarket" clinical trial of a new braided stent with a customized simulation software.

METHODS

A stent system with 3 mesh density types (16, 24, and 32 wire mesh) was designed based on computational flow dynamics technology, and a simulation software (virtual stent planner [VSP]) was developed for the optimal stent deployment planning. Stents were selected after simulation on preoperative 3D-processed angioimages, and accuracy of the VSP was evaluated.

RESULTS

Thirty-three unruptured intracranial aneurysms were successfully treated with VSP guidance. Twenty aneurysms (61%) were anterior circulation aneurysms, and 13 (39%) were posterior circulation aneurysms. The average aneurysm size was 7.1 mm, and the mean follow-up period was 19.2 months (11-39.0). There was no major recurrence or retreatment during follow-up, 2 morbidity cases, and no mortality. VSP planning presented slightly smaller stent dimensions compared with postdeployment: 24.2 vs 25.5 mm average, error -1.3 mm, and difference rate-5.46%.

CONCLUSION

Based on this result, the new stents and software guidance system were approved by the Ministry of Health and Welfare as a combined medical device. VSP provided precise deployment with minimal error compared with actual stent and can contribute to better stent deployment even for less experienced physicians.

The Enterprise stent…still useful after all these years

BACKGROUND

The Enterprise stent (Codman Neuro, Massachusetts, USA) received Food and Drug Administration (FDA) approval in 2007 for stent-assisted coiling (SAC). Since its introduction, newer stents and devices for aneurysm treatment have been developed resulting in a shift in the utilization of this stent from SAC to other off-label indications.

OBJECTIVE

To describe our experience with the Enterprise stent being used for SAC and other off-label indications.

METHODS

This is a multi-center retrospective review of the use of the Enterprise stent between 2018 and 2023. All patients in which the Enterprise stent was successfully deployed were included in the study.

RESULTS

Our study cohort comprised of 194 patients, mostly females (n = 112, 57.7%), with a mean age of 63.2 years ± 14.3. The Enterprise stent was used for SAC in only 24 (12.4%) patients and was used for rescue stenting in stroke in 101 patients (52.1%), treatment of intracranial stenosis in 53 patients (27.3%), treatment of in-stent stenosis in 1 patient (0.5%), and for treatment of dissections in 15 patients (7.7%). From 2018 to 2023, the use of Enterprise stents for SAC significantly decreased (p < 0.0001) while the use of Enterprise stents for non-SAC purposes was insignificantly variable (p = 0.05).

CONCLUSION

Our study shows that the Enterprise stent remains a reliable tool in neuroendovascular procedures, even if its original intended use has been supplanted by other devices.

Three-dimensional reconstruction imaging by C-arm computed tomography accurately visualizes in-stent neointimal formation in patients with stent-assisted coil embolization

Background

Stent apposition to the vessel wall and in-stent neointimal formation after stent-assisted coil embolization for intracranial aneurysm are important factors associated with postoperative thromboembolic complications. No assessment methods have been established to depict 3-dimensional (3D) all-round in-stent neointimal formation.

Objective

To demonstrate the superiority of Dyna-3D imaging assessment as a modality for all-round ISNF in comparison with conventional two-dimensional digital subtraction angiography (2D-DSA).

Methods

Consecutive patients who underwent braided stent-assisted coil embolization for unruptured aneurysm between November 2016 and September 2021 were enrolled. Radiological assessments for stent apposition to the parent vessel after stent deployment and in-stent neointimal formation after 3 months were obtained. Dyna-3D was reconstructed by overlapping a plain image showing stent struts with a rotational DSA image showing the vessel lumen. Reconstructed Dyna-3D images can be rotated to any angle on the screen to evaluate to stent apposition around the vessel and in-stent neointimal formation in 3D, for comparison with 2D-DSA evaluations.

Results

Among the 73 patients enrolled, 70 patients (96%) showed complete stent wall apposition on Dyna-3D. Higher intra-rater agreement was confirmed on assessment of in-stent neointimal formation with Dyna-3D (Cohen's κ = 0.811) than with conventional 2D-DSA (Cohen's κ = 0.517). in-stent neointimal formation could not be confirmed on conventional imaging in 9 cases (16%) and on Dyna-3D in 2 cases (3%). The number of in-stent neointimal formations rated as stent wire completely outside the endothelial line was significantly higher with Dyna-3D than with 2D-DSA (p = 0.0001).

Conclusion

All-round 3D evaluation by Dyna-3D imaging appears useful for confirming in-stent neointimal formation after braided stent deployment in patients after stent-assisted coil embolization.

Additional rescue stenting with Neuroform Atlas stents during stent-assisted coiling of saccular aneurysms

OBJECTIVE

Overlapping stenting is sometimes attempted during endovascular treatment of cerebral aneurysm as a rescue for coil herniation, stent mal-positioning, or in-stent thrombosis. We retrospectively evaluated the efficacy and safety of additional rescue stenting (ARS) in telescoping fashion with Neuroform Atlas stent (NAS) during stent-assisted coiling of saccular aneurysms.

METHODS

We collected clinical and radiological data of patients with saccular aneurysms treated with ARS using NASs between March 2018 and December 2021. Y or X-stent-assisted coiling technique was excluded.

RESULTS

Eighteen unruptured and 5 ruptured aneurysms in 23 patients were treated with ARS using NASs. Sizes of aneurysms ranged from 2.0 mm to 10.0 mm (mean: 5.0 mm). Immediate angiographic results were complete occlusion in 11 aneurysms, residual neck in 4 aneurysms, and residual sac in 8 aneurysms. Peri-operative morbidity was 4.3 %. Nineteen of 23 patients underwent follow-up conventional angiography (mean, 9.9 months). Results showed progressive occlusion in 10 (52.6 %) cases and asymptomatic in-stent stenosis in 3 (15.8 %) cases. At the end of the observation period (mean, 17.4 months), all 18 patients without subarachnoid hemorrhage had excellent clinical outcomes (mRS of 0), except one (mRS of 1). Of five patients with subarachnoid hemorrhage, four had a favorable outcome (mRS of 0-1), while the other one was dependent (mRS of 4).

CONCLUSION

In this report on 23 patients, ARS with NASs for treating saccular aneurysms showed good technical safety with favorable clinical and angiographic outcomes. However, delayed in-stent stenosis was not uncommon. Thus, regular imaging follow-up is required.

Braided stent-assisted coil embolization versus laser engraved stent-assisted coil embolization in patients with unruptured complex intracranial aneurysms

PURPOSES

Braided and laser-cut stents both are efficacious and safe for coiling intracranial aneurysms. The study aimed to compare outcomes following braided stent-assisted coil embolization versus laser engraved stent-assisted coil embolization in 266 patients who were diagnosed with unruptured intracranial aneurysms of different types and locations.

METHODS

Patients with unruptured complex intracranial aneurysms underwent braided (BSE cohort, n = 125) or laser engraved (LSE cohort, n = 141) stent-assisted embolization.

RESULTS

The deployment success rate was higher for patients of the LSE cohort than those of the BSE cohort (140 [99%] vs. 117 [94%], p = 0.0142). Seventy-one (fifty-seven percentages) and 73 (52%) were coil embolization procedure success rates of the BSE and the LSE cohorts. Periprocedural intracranial hemorrhage was higher in patients of the BSE cohort than those of the LSE cohort (8 [6%] vs. 1 [1%], p = 0.0142). Four (three percentages) patients from the LSE cohort and 3 (2%) patients from the BSE cohort had in-stent thrombosis during embolization. Permanent morbidities were higher in patients of the LSE cohort than those of the BSE cohort (8 [6%] vs. 1 [1%], p = 0.0389). Higher successful procedures (76% vs. 68%) and fewer postprocedural intracranial hemorrhage (0% vs. 5%) and mortality (0% vs. 5%) were reported for patients of the BSE cohort in posterior circulation aneurysmal location than those of the LSE cohort. Laser engraved stent has fewer problems with deployment and may have better periprocedural and follow-up outcomes after embolization.

CONCLUSIONS

Braided stent-assisted embolization should be preferred when the aneurysm is present in the posterior circulation.

Effect of Stent Porosity, Platelet Function Test Usage, and Dual Antiplatelet Therapy Duration on Clinical and Radiographic Outcomes After Stenting for Cerebral Aneurysms: A Meta-Analysis

BACKGROUND

The use of stents with various porosities for treating cerebral aneurysms requires dual antiplatelet therapy (DAPT) without clear guidelines on the utility of platelet function tests (PFTs) and the duration of DAPT. We sought to determine the effects of stent porosity, PFT usage, and DAPT duration on the radiographic and clinical outcomes after stenting of cerebral aneurysms.

METHODS

PubMed was searched on March 29, 2021 for studies of cerebral aneurysm stenting that had specified the stent type and DAPT duration. A random effects meta-analysis was used to measure the prevalence of nonprocedural thrombotic and hemorrhagic events, clinical outcomes, aneurysm occlusion, and in-stent stenosis stratified by stent porosity, PFT usage, and DAPT duration.

RESULTS

The review yielded 105 studies (89 retrospective and 16 prospective) with 117 stenting cohorts (50 high porosity, 17 intermediate porosity, and 50 low porosity). In the high-, intermediate-, and low-porosity stenting cohorts, PFT usage was 26.0%, 47.1%, and 62.0% and the mean DAPT duration was 3.51 ± 2.33, 3.97 ± 1.92, and 5.18 ± 2.27 months, respectively. The intermediate-porosity stents showed a reduced incidence of hemorrhagic events (π = 0.32%) compared with low-porosity stents (π = 1.36%; P = 0.01) and improved aneurysm occlusion (π = 6.18%) compared with high-porosity stents (π = 14.42%; P = 0.001) and low-porosity stents (π = 11.71%; P = 0.04). The prevalence of in-stent stenosis was lower for the intermediate-porosity (π = 0.57%) and high-porosity (π = 1.51%) stents than for the low-porosity stents (π = 3.30%; P < 0.05). PFT use had resulted in fewer poor clinical outcomes (π = 3.54%) compared with those without PFT use (π = 5.94%; P = 0.04). The DAPT duration had no effect on the outcomes.

CONCLUSIONS

In the present meta-analysis, which had selected for studies of cerebral aneurysm stenting that had reported the DAPT duration, intermediate-porosity stents and PFT use had resulted significantly improved outcomes. No effect of DAPT duration could be detected.

Microcatheter movement in the aneurysm due to low-profile visualized intraluminal support deployment: An in vitro study

BACKGROUND

When a microcatheter is in the aneurysm, it may move due to low-profile visualized intraluminal support (LVIS) deployment. This study was designed to determine this mechanism.

METHODS

Six silicon aneurysm models were created by combining the aneurysm location (side wall or bifurcation) and the parent vessel configuration (straight, ipsilateral bending, or contralateral bending). After adjusting the microcatheter tip position in the aneurysm by pushing or pulling, an LVIS stent was deployed to cover the aneurysm neck, and the changes in the microcatheter tip position was measured. Pushing and pulling were performed 15 times each for each model, for a total of 180 experiments.

RESULTS

In all experiments, the microcatheter tip moved with LVIS deployment. The total movement distance was 3.00±1.59 mm, which was significantly different between the push and pull groups (p = 0.049), between the three side-wall aneurysm models (p<0.0001), and between the three bifurcation aneurysm models (p<0.0001). Backward movement in the aneurysm occurred in 21% (37/180). The frequency of backward movement was significantly different between the side-wall and bifurcation aneurysm models (p = 0.0265) and between the push and pull groups (p<0.0001). The forward movement distance was significantly different between the side-wall (n = 78) and bifurcation (n = 65) aneurysm models (p<0.0001).

CONCLUSIONS

The aneurysm location, the parent vessel configuration, and adjustment of the microcatheter tip position by pushing or pulling may affect the total movement distance and forward/backward movement of the microcatheter tip due to LVIS deployment.

Is it safe to discontinue antiplatelet medication after stent-assisted coil embolization? If so, when is the best time?

PURPOSE

Antiplatelet maintenance after stent-assisted coil embolization (SACE) is generally considered essential to avoid post-procedural thromboembolic complications. However, there is still debate as to whether it is safe to discontinue antiplatelet drugs after SACE or when is the best time to do so. We investigate herein the clinical outcomes experienced by patients who discontinue antiplatelet agents after SACE.

METHODS

From a prospective database, we retrieved the data for 120 consecutive patients (harboring 130 aneurysms) in whom antiplatelet agents were discontinued after SACE between January 2010 and December 2019. We defined thromboembolic complications associated with discontinuation as neurologic or radiographic ischemia that occurred within 6 months of discontinuation of antiplatelet agents; the lesion was required to be correlated with the stented artery.

RESULTS

The mean time of discontinuation of antiplatelet medication was 31.4 ± 18.3 months after SACE (median, 26 months). The majority of patients stopped antiplatelet medication between 18 and 36 months after SACE (74 patients, 61.6%). Laser-cut closed-cell stent was most commonly applied in 91 aneurysms (70.0%), followed by braided closed-cell (n=29; 22.3 %) and laser-cut open-cell stent 10 (7.7 %). No patients experienced cerebral ischemia related to discontinuation of antiplatelet medication.

CONCLUSION

Our preliminary study suggests that it may be safe to discontinue antiplatelet medication after SACE in patients at low risk for ischemia. The optimal time to discontinue might be around 18 to 36 months after SACE. Large cohort-based studies or randomized clinical trials are warranted to confirm these results.

Utility of low-profile visualized intraluminal support (LVIS™) stent for treatment of acutely ruptured bifurcation aneurysms: A single-center study

Objective

Stent-assisted coiling has been increasingly used in the treatment of intracranial aneurysms. However, its application in ruptured bifurcation aneurysms remains controversial and challenging. This study aimed to present the safety and feasibility of low-profile visualized intraluminal support (LVIS™, LVIS, and LVIS Jr.) stent for acutely ruptured bifurcation aneurysms.

Methods

A total of 41 patients with acutely ruptured intracranial aneurysms arising at the bifurcation were treated with LVIS™ stent-assisted coiling in our hospital between January 2017 and December 2021. The clinical data and angiographic results of the patients were analyzed.

Results

Among these patients, all stents were successfully implanted. According to the immediate angiographic results, 29 aneurysms (70.7%) were completely occluded. Intraoperative thrombosis and hemorrhage occurred in two and one cases, respectively. No post-operative thrombosis or rebleeding events were observed. The clinical follow-up of all patients revealed that 38 (92.7%) cases had favorable outcomes (modified Rankin scale: 0-2). The angiographic results available for the 36 patients during the follow-up period revealed complete occlusion was achieved in 30 patients (83.3%) and residual neck in six patients.

Conclusion

The LVIS™ stent-assistant coiling is a safe and feasible option for acutely ruptured bifurcation aneurysms. Further studies with a prospective design, a larger sample size, and long-term follow-up are needed to validate these findings.

Stent-assisted coiling vs. coiling alone of ruptured tiny intracranial aneurysms: A contemporary cohort study in a high-volume center

Objective

This study aims to compare the safety and efficacy of stent-assisted coiling (SAC) with those of coiling alone (CA) for the treatment of ruptured tiny intracranial aneurysms.

Methods

We enrolled 245 patients with ruptured tiny intracranial aneurysms treated with coil embolization. Patients were grouped into SAC and CA groups. Baseline characteristics, periprocedural complications, clinical outcomes, and angiographic results were compared between the two groups. In addition, a subgroup analysis was conducted in the SAC group, and patients were regrouped into low-profile visualized intraluminal support (LVIS) and laser-cut groups to compare the perioperative procedure-related complications and clinical and angiographic follow-up outcomes.

Results

All baseline characteristics were equivalent between the two groups except for aneurysm size and dome-to-neck aspect ratio. The rates of overall procedure-related complications, intraprocedural rupture, postoperative early rebleeding, intraprocedural thrombosis, postprocedural thrombosis, and procedure-related mortality were comparable between the two groups (P = 0.105, 0.145, 0.308, 1.000, 1.000, 0.160, respectively). Nevertheless, the rate of hemorrhagic complication in the SAC group was significantly higher (P = 0.023). The angiographic follow-up outcomes showed that the SAC group had a higher complete occlusion rate and lower recurrence rate (88.2 vs. 67.1%, 5.4 vs. 15.2%, P = 0.001). The clinical outcomes at discharge and follow-up between the two groups demonstrated no significant differences (P = 0.192 and P = 0.085, respectively). For subgroup analysis, LVIS stents were associated with a significantly higher rate of complete occlusion (P = 0.014) and a lower rate of intraprocedural rupture (p = 0.021). Moreover, multivariate analysis showed that there were no predictors for the overall, hemorrhagic, and ischemic procedure-related complications, while Raymond class was an independent predictor of retreatment (OR = 3.508, 95% CI 1.168-11.603; P = 0.029).

Conclusion

Stent-assisted coiling may increase the incidence of hemorrhagic events with favorable angiographic results and comparable clinical outcomes compared with stand-alone coiling. Nevertheless, LVIS stent could improve the safety compared with lazer-cut stent. Simultaneously, considering the better long-term effect, LVIS stent-assisted coiling may be a preferable choice for ruptured tiny intracranial aneurysms.

Initial and mid-term results of LEO Baby stent-assisted coiling of intracranial aneurysms located in small arteries: A single-center experience with 131 consecutive patients

Background and purpose

Low-profile intracranial stents such as the LEO Baby stents are considered to be advantageous for the treatment of intracranial aneurysms originating from small arteries. This study aimed to evaluate the initial and mid-term clinical and angiographic results of LEO Baby stents in stent-assisted coiling of intracranial aneurysms with small parent arteries (<2.5 mm).

Methods

We performed a retrospective study to identify 131 patients with aneurysms arising from small parent arteries treated with Leo Baby stent-assisted coiling in a single institution between October 2018 and June 2021. We assessed the immediate and progressive aneurysm occlusion rates, procedure-related complications, and clinical outcomes.

Results

A total of 131 patients with 135 aneurysms were identified, including 65 (48.1%) cases of acutely ruptured aneurysms. Technical success was achieved in all cases (100%). The immediate angiography showed complete occlusion in 111 aneurysms (82.2%), neck remnants in 19 (14.1%), and residual sac in 5 (3.7%). Procedure-related complications occurred in 14 cases (10.3%), including 13 (9.6%) thromboembolic complications and 1 (0.7%) hemorrhagic complication. Six-month follow-up angiography was achieved in 106 (78.5%) aneurysms, which showed complete occlusion in 102 (96.2%) aneurysms, neck remnants in 2 (1.9%), and residual sac in 2 (1.9%). Clinical follow-up was available in all patients with a median duration of 6.8 months, and favorable clinical outcomes (modified Rankin Scale score: 0–2) reached 91.6%. The mortality rate was 4.6%.

Conclusion

Our results demonstrate that stent-assisted coiling of intracranial aneurysms located on small arteries using LEO Baby stents is technically feasible, highly effective, and has midterm durability in aneurysmal occlusion.

Hemodynamic Comparison of Treatment Strategies for Intracranial Vertebral Artery Fusiform Aneurysms

Objective

This study comparatively analyzed the hemodynamic changes resulting from various simulated stent-assisted embolization treatments to explore an optimal treatment strategy for intracranial vertebral artery fusiform aneurysms. An actual vertebral fusiform aneurysm case treated by large coil post-stenting (PLCS) was used as a control.

Materials and Methods

A single case of an intracranial vertebral artery fusiform aneurysm underwent a preoperative and eight postoperative finite element treatment simulations: PLCS [single and dual Low-profile Visualized Intraluminal Support (LVIS)], Jailing technique (single and dual LVIS both simulated twice, Pipeline Embolization Device (PED) with or without large coils (LCs). Qualitative and quantitative assessments were performed to analyze the most common hemodynamic risk factors for recurrence.

Results

Jailing technique and PED-only had a high residual flow volume (RFV) and wall shear stress (WSS) on the large curvature of the blood flow impingement region. Quantitative analysis determined that PLSC and PED had a lower RFV compared to preoperative than did the jailing technique [PED+LC 2.46% < PLCS 1.2 (dual LVIS) 4.75% < PLCS 1.1 (single LVIS) 6.34% < PED 6.58% < Jailing 2.2 12.45% < Jailing 1.2 12.71% < Jailing 1.1 14.28% < Jailing 2.1 16.44%]. The sac-averaged flow velocity treated by PLCS, PED and PED+LC compared to preoperatively was significantly lower than the jailing technique [PED+LC = PLCS 1.2 (dual LVIS) 17.5% < PLCS 1.1 (single LVIS) = PED 27.5% < Jailing 1.2 = Jailing 2.2 32.5% < Jailing 1.1 37.5% < Jailing 2.1 40%]. The sac-averaged WSS for the PLCS 1.2 (dual LVIS) model was lower than the PED+LC, while the high WSS area of the Jailing 1 model was larger than for Jailing 2 [PLCS 1.2 38.94% (dual LVIS) < PED+LC 41% < PLCS 1.1 43.36% (single LVIS) < PED 45.23% < Jailing 2.1 47.49% < Jailing 2.2 47.79% < Jailing 1.1 48.97% < Jailing 1.2 49.85%].

Conclusions

For fusiform aneurysms, post large coil stenting can provide a uniform coil configuration potentially reducing the hemodynamic risk factors of recurrence. Flow diverters also may reduce the recurrence risk, with long-term follow-up required, especially to monitor branch blood flow to prevent postoperative ischemia.

LVIS-within-enterprise double-stent procedure without coiling beneficial as treatment of unruptured vertebral artery dissecting aneurysms

Stenting of vertebral artery dissecting aneurysms (VADAs) may promote mural apposition of intimal flaps, preserving the patency of injured vessels. Moreover, stent deployment may serve to alter intra-aneurysm flow, inducing saccular thrombus formation, neointimal development, and remodeling of injured vessels. Although an overlapping multistent strategy with coiling has proven successful in this setting, yielding good anatomic and clinical outcomes, coiling may be technically infeasible in some VADAs with unfavorably configured circumferential elevations. Herein, we describe three patients with VADAs for whom coiling was deemed technically problematic. Each underwent double stenting (LVIS within Enterprise), without coil insertion, using local anesthesia. Conventional angiographic follow-up regularly disclosed excellent saccular occlusion and subsequent remodeling of stented arteries. LVIS-within-Enterprise double stenting may be of particular benefit in patients with VADAs, the Enterprise providing outer support to minimize stent bulging (as a fusiform aneurysm) as the inner LVIS reinforces flow diversion.

Midterm Outcomes After Low-Profile Visualization Endoluminal Support or Atlas Stent-Assisted Coiling of Intracranial Aneurysms: A Propensity Score Matching Analysis

BACKGROUND

The interplay of various commercially available stents during coil embolization of intracranial aneurysms and their ultimate impact are subject to debate.

OBJECTIVE

To compare midterm outcomes of Low-Profile Visualization Endoluminal Support (LVIS) (MicroVention Inc) and Atlas (Stryker) stent-assisted coiling procedures.

METHODS

A total of 459 intracranial aneurysms subjected to coil embolization using LVIS (n = 318) or Atlas stents (n = 141) between April 2015 and December 2019 were eligible for study. To assess occlusive status postembolization, magnetic resonance angiography and/or conventional angiography were used. The Raymond classification was applied to categorize recanalization. Our analysis was propensity score matched according to probability of stent type deployed.

RESULTS

Eventually, 41 aneurysms (8.9%) displayed recanalization (minor, 28; major, 13) 6 mo after coiling. Patient age (P = .018), sex (P = .015), aneurysmal location (P < .001), and type of aneurysm (P < .001) differed significantly by group. Overall and major recanalization rates at midterm were similar in both groups (9.1% and 8.5% vs 3.1% and 2.1%, respectively), and there was no significant difference even after 1:1 propensity score matching (odds ratio [OR] = 0.75 [P = .514] and OR = 0.75 [P = .706], respectively).

CONCLUSION

In stent-assisted coil embolization of intracranial aneurysms, midterm outcomes of LVIS and Atlas device groups were similar, despite theoretic LVIS superiority. Further randomized comparative studies are needed to confirm our findings.

Endovascular treatment of vertebral and basilar artery aneurysms with low-profile visualized intraluminal support device

Background

The Low-profile Visualized Intraluminal Support (LVIS) device is a self-expanding, nitinol, single-braid, closed-cell device that was recently developed for endovascular embolization of intracranial aneurysms. However, current knowledge regarding the use of LVIS devices to treat vertebral and basilar artery aneurysms is limited. We aimed to evaluate the feasibility, efficacy, and safety of the LVIS device for treating vertebral and basilar artery aneurysms.

Methods

Between January 2015 and December 2017, patients with vertebral and basilar artery aneurysms treated using LVIS stents were enrolled in this study. We analyzed patients’ demographic, clinical and aneurysmal characteristics, procedural details, complications, and angiographic and clinical follow-up results.

Results

We identified 63 patients with 64 vertebral and basilar artery aneurysms who underwent treatment with (n = 59) or without (n = 5) LVIS stenting, including 10 patients with ruptured aneurysms. Forty-one aneurysms were located at the vertebral artery, and 23 at the basilar artery. Intraprocedural-related complications developed in three (4.8%) patients, while none of these patients developed morbidities or died during follow-up. Three patients developed post-procedural complications (4.8%). Two patients experienced ischemic events immediately post-procedure. A minor permanent morbidity developed in one of the two patients (1.6%). The mortality rate was 1.6%, for that the patient died of brainstem hemorrhage after 1 month of follow-up. At a mean follow-up of 12.5 months, 39/43 (90.7%) patients had stable or improved aneurysms, and four (9.3%) had recanalized.

Conclusions

LVIS device of vertebral and basilar artery aneurysms may be an acceptable safety profile and may represent a reasonable treatment option in the short-term. Long-term and larger cohort studies are necessary to validate our results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02180-1.

Low-Profile Visualized Intraluminal Support Jr Braided Stent Versus Atlas Self-Expandable Stent for Treatment of Intracranial Aneurysms: A Single Center Experience

BACKGROUND

The Neuroform Atlas Stent and Low-profile Visualized Intraluminal Support (LVIS) and LVIS Jr stents are used to treat intracranial aneurysms (IAs), but their safety, performance, and outcomes have not been directly compared.

OBJECTIVE

To compare the technical performance and outcomes of Atlas and LVIS Jr stents for treatment of IAs.

METHODS

IAs treated by stent-assisted coiling using an Atlas (Stryker, Kalamazoo, Michigan) or LVIS Jr (MicroVention, Aliso Viejo, California) device between January 2014 to November 2019 were retrospectively evaluated. Patient demographics, aneurysm size and location, technical difficulties, and clinical and angiographic follow-up were analyzed.

RESULTS

A total of 116 patients, (mean age 64.2 ± 11.8 yr, 72.7% female) with 121 aneurysms underwent stent-assisted coiling with deployment of Atlas (n = 64) or LVIS Jr (n = 57) stents. Mean aneurysm size was 6.2 ± 2.7 mm. Immediate rates of Raymond-Roy (RR) 1/2 were 89.0% (57/64) and 80.7% (46/57) for the Atlas and LVIS Jr groups, respectively. Neither group had major postoperative thromboembolic complications; however, 15.8% (9/57) of the LVIS Jr procedures had technical issues. Additionally, 88.5% (46/52) and 91.2% (33/36) of patients in the Atlas and LVIS Jr groups had RR 1/2 at a mean follow-up of 13.6 and 18.7 mo, respectively.

CONCLUSION

Treatment of IAs with Atlas and LVIS Jr stents results in favorable clinical outcomes and angiographic results at follow-up, with low rates of recurrence and retreatment, suggesting both devices are safe and effective. Notably, LVIS Jr had more technical problems than Atlas.

Factors related to microcatheter passage through the trans-cell approach using a low-profile visualized intraluminal support device: an in-vitro study

BACKGROUND AND PURPOSE

The trans-cell approach using a low-profile visualized intraluminal support (LVIS) device is sometimes used for aneurysm coil embolization. However, factors related to microcatheter passage remain uninvestigated. We aimed to examine in-vitro factors related to microcatheter passage using the trans-cell approach with an LVIS.

METHODS

Silicone vessel models (inner diameter, 4 mm) were created with different bend segments and a 4-mm hole assuming an aneurysm neck on the side of the greater curvature. The LVIS Blue (4.5 × 32 mm) was deployed at the bend segment, and passability on the trans-cell surface was evaluated by passing the microcatheter along the micro guidewire. A total of 800 passage experiments were performed using two types of microcatheter, ten types of silicone vessel, four cell widths, five cells with the same LVIS device, and two micro guidewire directions in the aneurysm.

RESULTS

The Headway Duo microcatheter (35.5%, 142/400) tended to have better passability compared with the Headway 17 microcatheter (29.3%, 117/400) (p = 0.070). As the cell width and angle between the trans-cell surface and microcatheter direction increased, passability significantly increased (p = 0.027 and p < 0.001, respectively). There was no significant difference in passability when the micro guidewire was directed to the proximal side versus the distal side (p = 0.45).

CONCLUSIONS

A large cell width and an obtuse angle between the trans-cell surface and microcatheter direction facilitated good passability. Although statistically marginal, microcatheters with small ledges and small tips had relatively good passability.

Endovascular Treatment of Ruptured Wide-Necked Anterior Communicating Artery Aneurysms Using a Low-Profile Visualized Intraluminal Support (LVIS) Device

Objective: To evaluate the safety and efficacy of low-profile visualized intraluminal support (LVIS) stent-assisted coiling for the treatment of ruptured wide-necked anterior communicating artery (ACoA) aneurysms.

Methods: The clinical and angiographic data of 31 acutely ruptured wide-necked ACoA aneurysms treated with LVIS stent-assisted coiling between January 2014 and December 2018 were retrospectively reviewed.

Results: All stents were successfully deployed. The immediate angiographic results were modified Raymond-Roy class I in 27 cases, modified Raymond-Roy class II in 2 cases, and modified Raymond-Roy class IIIa in 2 cases. Intraoperative thrombosis and postoperative aneurysmal rebleeding occurred in one case each. Two patients (6.5%) who were admitted due to poor clinical grade conditions died during hospital admission as a result of initial bleeding. Angiographic follow-up (mean: 12.9 months) was performed for 26 patients, the results of which demonstrated that 25 aneurysms were completely occluded and one was class II. The last clinical follow-up (mean: 25.3 months) outcomes demonstrated that 27 patients had favorable clinical outcomes and two had poor clinical outcomes.

Conclusion: LVIS stent-assisted coiling for ruptured wide-necked ACoA aneurysms was safe and effective, with a relatively low rate of perioperative complications and a high rate of complete occlusion at follow-up.

Rescue permanent LVIS stenting with post-stenting angioplasty after failed mechanical thrombectomy for refractory internal carotid artery occlusion at the paraclinoid segment: two-case report

BACKGROUND

Previous studies indicated the effectiveness of permanent stenting when dealing with retriever-failed refractory large vascular occlusion (LVO). Variety types of stents were implanted permanently to achieve recanalization. Low-profile visualized intraluminal support (LVIS) is generally used as a supportive device for embolization of intracranial aneurysm. Its specific structural and functional characteristics contribute to its potential of treating LVO.

CASES PRESENTATION

A 51-year-old male was transferred to our stroke center because of conscious disturbance with the weakness of the left upper limb. The National Institute of Health Stroke Scale (NIHSS) was 24; the Glasgow Coma Scale (GCS) was 10. Digital subtraction angiography (DSA) showed that his paraclinoid segment of R-ICA was occluded due to hard clot embolization. Thrombectomy was performed 6 times, but the occlusion remained. Finally, LVIS was implanted permanently and post-dilation was performed, which successfully recanalized the artery (eTICI 2c). The post-operative NIHSS and GCS were 20 and 11, respectively, which were 10 and 14 when discharged. Another patient was a 71-year-old male who suffered weakness of left limbs. NIHSS was 15; GCS was 11. DSA confirmed that the paraclinoid segment of his R-ICA was occluded due to hard clot embolization. Totally 6 times of mechanical thrombectomy, angioplasty, and tirofiban infusion were performed, which failed to recanalize the artery. In the end, LVIS implantation with post-dilation was performed, and full recanalization was achieved (mTICI 3). The post-operative NIHSS and GCS were 9 and 15, respectively, which were 3 and 15 when discharged.

CONCLUSIONS

These 2 cases invited LVIS into the treatment of refractory occlusion due to hard clot embolization at the paraclinoid segment, and the outcomes were preferable because of the higher visibility, higher flexibility, and lower cell size of LVIS.

Neurosurgical management of aneurysms of the vertebrobasilar system: increasing indications for endovascular therapy with a continued role for open microneurosurgery

Aneurysms of the vertebrobasilar system remain among the most challenging subsets of aneurysms to treat with an open surgical approach. Since Charles Drake's pioneering work in the 1960s, several advances in microsurgical techniques have improved outcomes and feasibility in the open surgical management of these aneurysms. In parallel, the field of endovascular neurosurgery has provided several safe and effective treatment options. Multiple trials have suggested that endovascular therapy for aneurysms of the vertebrobasilar system is superior to open surgical management in most cases. In some instances, however, open surgical management likely represents a more effective and durable option relative to endovascular therapy. Therefore, continued training of future cerebrovascular specialists in open surgery of vertebrobasilar aneurysms remains crucial. With widespread utilization of endovascular techniques, however, proper exposure of trainees to such aneurysms is growing increasingly difficult. In this review, we discuss the recent advances in the endovascular management of vertebrobasilar aneurysms while also emphasizing the continued importance of open microneurosurgery in such cases.

Endovascular treatment of patients with intracranial aneurysms: feasibility and successful employment of a new low profile visible intraluminal support (LVIS) EVO stent

BACKGROUND AND PURPOSE

Low-profile self-expandable stents have increased the number of intracranial aneurysms treated by endovascular means. The new low-profile visible intraluminal support device LVIS EVO (Microvention), the successor of LVIS Jr, is a self-expandable and retrievable microstent system, designed for implantation into intracranial arteries with a diameter up to 2.0 mm. In this retrospective study we aimed to elucidate the technical feasibility and clinical safety of the novel LVIS EVO stent for stent-assisted coil embolisation of intracranial aneurysms.

MATERIALS AND METHODS

A single centre technical report of the first six consecutive cases of stent-assisted coil embolisation with the novel LVIS EVO stent for the treatment of unruptured or recanalised intracranial aneurysms. Records were made of basic demographics, aneurysmal characteristics, device properties and related technical details, adverse events, clinical outcomes and occlusion rates on available radiological follow-up.

RESULTS

Six LVIS EVO devices were successfully implanted in all subjects to treat a total number of six intracranial aneurysms. No device-related intraprocedural complications were seen. At early clinical follow-up six out of six (100%) patients had a modified Ranking score of 0-1. Early angiographic and cross-sectional radiological follow-up, available in five out of six (83.3%) of the patients confirmed unchanged aneurysmal occlusion rates. A minor, transitory neurological deficit was recorded in one of the six (16.6%) patients. Mortality was 0%.

CONCLUSIONS

Preliminary experience in this subset of our patients confirms a notably improved technical behaviour of the novel LVIS EVO stent system when compared to its ancestor LVIS Jr. The enhanced visibility of the stent and the refined delivery/retrieval capabilities of the stent further increase the safety margins of the devices profile, especially in cases of tortuous anatomy.

Stent-Assisted Coiling of Unruptured MCA Aneurysms Using the LVIS Jr. Device: A Multicenter Registry

Purpose: The low-profile visualized intraluminal support junior (LVIS Jr.) is a new generation low-profile braided stent. Our aim was to evaluate the safety and efficacy of the LVIS Jr. in the stent-assisted coiling of unruptured middle cerebral artery (MCA) aneurysms. This was a multicenter retrospective study. Patient demographics, aneurysm characteristics, procedural details, complications, and the results of clinical and imaging follow-up were analyzed. Four centers participated in the study. A total of 162 consecutive patients with 162 unruptured MCA aneurysms were included for the analysis. The mean aneurysm size was 7.6 mm (range 2 to 37 mm) and 97.5% were wide-necked. Immediate postprocedural angiograms showed Raymond-Roy class 1 in 118 (72.8%), class 2 in 23 (14.2%), and class 3 in 21 patients (13%). Periprocedural complications occurred in 14 patients (8.6%). There were no procedure-related deaths. Follow-up imaging at 12–18 months post-procedure showed Raymond–Roy class 1 in 132 (81.5%), class 2 in 17 (10.5%), and class 3 in 13 patients (8%). There were 3 cases of in-stent stenosis (1.9%). All 162 patients had good clinical outcome (mRS score 0–2) at 90 days post-procedure. Stent-assisted coiling of unruptured MCA aneurysms with the LVIS Jr. stent is safe and effective, with high immediate and long-term total occlusion rates.

Early Multicenter Experience With the Neuroform Atlas Stent: Feasibility, Safety, and Efficacy

BACKGROUND

The Neuroform Atlas stent™ (by Stryker, Fremont, California) represents the most recent widely available upgrade to intracranial stenting, providing a laser cut open cell stent with a diameter of 3.0 to 4.5 mm that is delivered through an 0.017-inch microcatheter.

OBJECTIVE

To report our initial multicenter experience of the safety, efficacy, and feasibility of the Atlas stent used for treating aneurysms, as well as one case of intracranial stenosis and one carotid artery dissection as well as other pathologies.

METHODS

A retrospective multicenter study of subjects treated with Atlas stent during the period 2018 to 2019.

RESULTS

The total number of patients included in our analysis was 71 patients. The stent was utilized to treat 69 aneurysm cases. Of the aneurysms, 36% presented with acute rupture and 56% of the ruptured aneurysms were high grade. Mean aneurysm dimension was 7 mm with an average neck width of 4.1 mm. Around 30% had received prior treatment. Telescoping or Y-stent was used in 16% of cases. We did not observe any symptomatic major complications in our series. Asymptomatic major complications were seen in 7 patients (10.1%); technical complications occurred in 4.3%. Immediate modified Raymond-Roy-occlusion-outcome class I/II was observed in 87%, and this increased to 97.7% at latest follow-up, which was at 4 mo; 91.8% of patients achieved favorable clinical outcome, and mortality rate was 1.4%.

CONCLUSION

Our series demonstrates the safety, feasibility, and efficacy of the Atlas stent. The low complication rate and the high obliteration rate managing complex aneurysms, even in an acute ruptured setting, are notable.

Low-profile visible intraluminal support stent-assisted embolization therapy for intracranial dissecting aneurysms: A retrospective analysis of six cases

Endovascular Embolization (EVE) of aneurysms is a very effective and efficient treatment modality. Nevertheless, a few complications have been reported after EVE of aneurysms. Our study therefore evaluated the safety and efficacy of Low-profile Visible Intraluminal Support (LVIS) stentassisted EVE for intracranial Dissecting Aneurysms (DAs). We conducted a retrospective study to identify patients with DAs who were treated with LVIS stent from July 2015 to September 2018. The DAs were categoried into ruptured and unruptured. The arteries harbouring the aneurysm were identified in all cases. LVIS device stent assisted coil EVE treatment modality was utilized to treat all the patients. Surgical safety, immediate surgery outcome, recurrence rate and imaging follow-up results of all patients were analysed. The Glasgow Outcome Scale (GOS) score of all patients where assessed during discharge. Cerebral angiography of all patients were reevaluated on scheduled visits from three months up to one year after their operations. A total of Six DA patients were identified during our analysis. Four of the cases were ruptured DAs while two cases were unruptured. The DAs originated from the Internal Carotid Artery (ICA) in two cases, while in the remaining four cases, the DAs originated from vertebral artery (VA). Stents and coils were successfully implanted in all six patients. The DAs were embolized satisfactorily and the parent arteries were patent immediately after the operations. We obsereved 5 points GOS score in four cases and 4 points in two cases. No aneurysmal recurrece, no stent collapse or displacement was obsereved in all cases during follow-ups. Our study suggests that, LVIS stent-assisted EVE is simple, safe and effective in the treatment of DAs.

Follow-up outcomes of intracranial aneurysms treated using braided or laser-cut stents with closed-cell design: a propensity score-matched case-controlled comparison

BACKGROUND

The impact of various stents on patients with intracranial aneurysms who undergo stent-assisted coiling has been debated. We conducted this study to compare follow-up outcomes of coiling procedures involving braided or laser-cut stents with closed-cell design. A propensity score-matched case-controlled analysis was applied.

METHODS

A total of 413 intracranial aneurysms consecutively coiled using laser-cut (n=245) or braided stents (n=168) in procedures performed between September 2012 and June 2017 were eligible for study. Time-of-flight magnetic resonance angiography, catheter angiography, or both were used to gauge occlusive status after coiling. Recanalization was determined by Raymond classification (complete occlusion vs recanalization). A propensity score-matched analysis was conducted, based on probability of stent type in use.

RESULTS

Ultimately, 93 coiled aneurysms (22.5%) showed some recanalization (minor, 51; major, 42) during the follow-up period (mean 21.7±14.5 months). Patient gender (P=0.042), hyperlipidemia (P=0.015), size of aneurysm (P=0.004), neck size (P<0.001), type of aneurysm (P<0.001), and packing density (P=0.024) differed significantly by group. Midterm and cumulative recanalization incidence rates in the braided-stent group were initially lower than those of the laser-cut stent group (P=0.009 and P=0.037, respectively) but they did not differ significantly after 1:1 propensity score matching (midterm OR=0.88, P=0.724; cumulative HR=0.91, P=0.758).

CONCLUSION

In stent-assisted coiling of intracranial aneurysms, laser-cut and braided stent groups produced similar outcomes in follow-up. Consequently, product selection may hinge on suitability for deployment rather than anticipated results.

Outcomes of Stent-Assisted Coiling Using the Neuroform Atlas Stent in Unruptured Wide-Necked Intracranial Aneurysms

Objective

Although stent-assisted coiling (SAC) has been reported to be safe and effective in treating wide-necked aneurysms, the technique has procedure-related complications. Thus, we reported our experiences of SAC using the Neuroform Atlas stent in treating wide-necked aneurysms and evaluated the incidence of and risk factors for procedure-related complications.

Methods

From March 2018 to August 2019, we treated 130 unruptured wide-necked aneurysms in 123 patients with Neuroform Atlas stents. Angiographic results and clinical outcomes were reviewed retrospectively. Clinical and angiographic follow-up were performed in all cases (mean, 12.4 months) after the procedure.

Results

There were eight cases (6.2%) of procedure-related complications (two dissections, five thromboembolisms, and one hemorrhage) and two (1.5%) of delayed complications (one ischemia and one hemorrhage). There was one case (0.8%) of failure of stent deployment and one (0.8%) of suboptimal positioning of the stent. Follow-up angiography showed complete obliteration in 103 (79.2%), residual neck in 16 (12.3%), and residual aneurysm in 11 cases (8.5%). Aneurysm locations in the middle cerebral artery (odds ratio [OR], 2.211; p=0.046) and the anterior communicating artery (OR, 2.850; p=0.039) were associated with procedure-related complications on univariate analysis. However, no independent risk factor for procedure-related complications was noted in multivariate analysis.

Conclusion

The Neuroform Atlas showed a high rate of technical success. Good clinical and radiographic outcomes in early follow-up suggests that the device is feasible and safe. SAC of aneurysms on the middle cerebral artery or anterior communicating artery may require more attention to prevent possible procedure-related complications.

Effects of acute angle, proximal bending, and distal bending in the deployment vessels on incomplete low-profile visualized intraluminal support (LVIS) expansion: an in vitro study

BACKGROUND

A low-profile visualized intraluminal support (LVIS) device may incompletely expand during stent deployment in tortuous vessels. However, the cause of incomplete expansion remains uninvestigated. We aimed to examine in vitro the factors causing incomplete expansion in LVIS deployment by using various vessel models.

METHODS

A linear model group was created by connecting linear silicone tubes (inner diameter 4 mm) at both sides of the LVIS deployment vessel (inner diameter 4 mm) with different curvature angles of 10-140° at 10° intervals. For comparison, proximal and distal bending model groups were created, both with 90° bending on the proximal/distal larger curvature side of the deployment vessel. A single operator macroscopically deployed an LVIS (4.5×32 mm) four times in each model and 56 times in each group.

RESULTS

In each model group the LVIS deployment vessel with a narrow curvature angle incompletely expanded. Incomplete expansion occurred significantly more frequently in the distal bending model group (34%, 19/56) compared with that in the linear model group (14.3%, 8/56; p<0.001), as well as in the proximal bending model group (59%, 33/56) compared with that in the distal bending model group (p<0.05). Compared with the linear model group, the proximal bending model group had a significantly reduced angle between the LVIS and the direction of the LVIS pushing force, but no significant change was found in the distal bending model group compared with that in the linear model group.

CONCLUSIONS

Factors such as acute angle, distal bending, and proximal bending of the deployment vessel can cause incomplete LVIS expansion.

Optimum concentration of iodine contrast agent injection for best stent visualization using Neuroform Atlas stent during stent-assisted coil embolization: Case reviews based on in vitro experiments

Background:

The present study aimed to evaluate the influence of contrast agent concentration (Conc) on the visibility of Neuroform Atlas in vitro and in clinical cases.

Methods:

A plastic tube was filled with several Conc. in saline (experiment 1) and blood (experiment 2). Thereafter, the Neuroform Atlas was placed around the plastic tube in an acrylic shield case. In experiment 3, the Neuroform Atlas was placed in the internal carotid artery of the endo vascular evaluator endovascular training system with an injection of several Conc in saline. Five slices of the axial images obtained using the 3D-cone-beam computed tomography (3D-CBCT) with the digital subtraction angiography system were evaluated. A 1-cm² circular center, which showed the contrast agent in saline or blood, was determined as the region of interest, and its pixels were evaluated.

Results:

Radiation density (Rd) was directly proportional to the contrast agent in saline and blood (experiment 1: (Rd (pixel)) = 6.8495 × (concentration (%)) + 152.72 (R² = 0.99), experiment 2: (Rd (pixel)) = 6.2485 × (concentration (%)) + 167.42 (R² = 0.9966), experiment 3: (Rd (pixel)) = 10.287 × (concentration (%)) + 108.26 (R² = 0.993)]. Rd calculated similarly in our cases (concentration varied from 5% to 8%) was between the range of “Rd of experiment 2” and “Rd of experiment 3.”

Conclusion:

Based on our in vitro experiments, with 5–8% concentration, Neuroform Atlas stent deployment with complete neck coverage by the bulging stent and wall apposition was visualized on 3D-CBCT.

Endovascular Intervention with a Low-profile Visualized Intraluminal Support Stent Versus Surgical Clipping for Blood Blister-like Aneurysms : A Retrospective Study

PURPOSE

Blood blister-like aneurysms (BBAs) have a high risk of early recurrence and postoperative rebleeding. This study compared the clinical outcomes and complications between endovascular intervention with low-profile visualized intraluminal support (LVIS) stent-assisted coiling and the surgical clipping in patients with BBAs.

METHODS

This retrospective study enrolled 39 patients with BBAs who underwent endovascular intervention with LVIS stent-assisted coiling (n = 21) or surgical clipping (n = 18) between January 2013 and July 2018. Primary outcomes were mortality and modified Rankin scale (mRS). Secondary outcomes were hospital stay, intensive care unit (ICU) stay and operation parameters. Complications were also retrospectively collated.

RESULTS

At baseline, the two groups were well balanced in patient characteristics. The hospital stays, ICU stays, operation time and intraoperative infusion volume were all significantly lower in LVIS group than that in clipping group (p < 0.05). A second operation was performed in 6 cases in the clipping group but none in the LVIS group (p = 0.006). The mean mRS score in the LVIS group was significantly lower than that of the clipping group both at hospital discharge and final follow-up (p < 0.001). Adverse outcomes occurred in 1 case in LVIS group and 7 in clipping group, with significant difference (p = 0.015). Complications were reported in 8 cases in LVIS group and 16 cases in clipping group, with significant difference (p < 0.001).

CONCLUSION

The endovascular intervention with LVIS stent-assisted coiling has better prognosis than surgical clipping. It decreased the risk of a second operation and procedure-related complications compared with surgical clipping.

Stent-assisted coiling of broad-necked intracranial aneurysms with a new braided microstent (Accero): procedural results and long-term follow-up

Intracranial stents have expanded endovascular therapy options for intracranial aneurysms. The braided Accero stent is available for clinical use since May 2015. To date, no clinical reports on the stent are available. Purpose of this study was the evaluation of the safety and efficacy of the Accero stent in stent-assisted coiling. All patients, in whom implantation of the stent was performed, were included. Primary endpoints were good clinical outcome (mRS ≤ 2) and aneurysm occlusion grades 1 and 2 (Raymond Roy Occlusion Classification). Secondary endpoints were procedural and device-related complications with permanent disability or death, complications in the course, and the recanalization rate. Between September 2015 and August 2018, thirty-four aneurysms were treated with stent-assisted coiling using the Accero. Sixteen aneurysms were untreated, four of these were ruptured. Mild neurological complications occurred in 2/34 (5.9%) treatments. Two stent occlusions occurred during follow-up. No patient had a poor procedure- or device-related outcome. After an average of 15 months of follow-up, 28/30 aneurysms were completely or near-completely occluded. The Accero stent proved to be safe and effective in the treatment of broad-based intracranial aneurysms. The complication rate and the rate of successful aneurysm occlusions are similar to those of other stents.

Cerebral aneurysms treated with low-profile visualized intraluminal support device (LVIS Jr) Y-stent constructs: Technical experience with a single microcatheter technique

BACKGROUND

The LVIS Jr device holds a number of advantages but poses unique technical challenges compared to such, especially, complex multistent constructs. We report our experience with the technical feasibility and early to mid-term outcomes of Y-stent-assisted coiling with the LVIS Jr using a simple, single microcatheter technique.

METHODS

Using a departmental database, we retrospectively reviewed a single surgeon's experience with Y-stent-assisted coiling with LVIS Jr over a three-year period. Eighteen aneurysms in 17 patients were treated over this period. We assessed the technical success of the procedures, the initial and follow-up radiographic success with the modified Raymond-Roy occlusion score and follow-up clinical outcome with the modified Rankin scale.

RESULTS

All stents were successfully deployed, and 17 of 18 aneurysms were successfully coiled at the initial treatment for a technical success rate of 94.4%. Of the 17 aneurysms with follow-up imaging, all were modified Raymond-Roy grade 1 or 2. One aneurysm required retreatment for coil compaction and a growing neck. There were two immediate postprocedure symptomatic strokes and one delayed stroke related to antiplatelet non-compliance. The two immediate symptomatic strokes recovered to neurological baseline with no residual deficits by the time of discharge. The long-term morbidity rate was 5.5%. The mortality rate was 0%. All patients had a modified Rankin Scale ≤ 2 at most recent follow-up.

CONCLUSION

Treatment with LVIS Jr Y-stent constructs via a single microcatheter technique is technically feasible with good radiographic and clinical outcomes.

Incomplete stent apposition of low-profile visualized intraluminal support stents in the treatment of cerebral aneurysms

OBJECTIVE

This study retrospectively analyzed the risk factors, management strategies, and complications of incomplete stent apposition (ISA) of low-profile visualized intraluminal support (LVIS) stents after initial deployment in the treatment of cerebral aneurysms.

METHODS

The clinical characteristics of ISA or wall apposition (WA) of LVIS stent after initial deployment were analyzed. The risk factors of ISA were identified using univariate logistic regression analysis and multivariate logistic regression analysis. The clinical characteristics of ISA following different management strategies were also shown.

RESULTS

The retrospective study enrolled 303 patients with 315 LVIS stent-assisted aneurysms. Fifty-nine patients with 59 stents showed ISA after initial deployment. At the end of the study, the presence of ISA was only observed in eight patients (2.5%). The stent-subtended arc angle (>90) and the aneurysm of the internal carotid artery (ICA) were associated with ISA. The stent-subtended arc angle (>90) and stent size (4.5*20 mm) were independent risk factors of ISA. The incidence of thromboembolic events in the ISA group was significantly higher than that in the WA group. After the treatment of ISA, there was no significant difference in good outcomes between patients with ISA and those with WA after initial deployment.

CONCLUSIONS

ISA is more likely to occur at tortuous vessels. The stent-subtended arc angle (>90) and LVIS size (4.5*20 mm) were independent risk factors of ISA. ISA led to significantly increased incidence of thromboembolic events. However, ISA after initial deployment did not affect the patient's prognosis.

Long Term Outcome of In-Stent Stenosis after Stent Assisted Coil Embolization for Cerebral Aneurysm

Objective

The objective of this study was to evaluatelong-term radiologic prognosis and characteristics of in-stent stenosis (ISS) after stent assisted coiling (SAC) for cerebral aneurysm and analyze its risk factors.

Methods

Radiological records of 362 cases of SAC during 10 years were retrospectively reviewed. Patients were included in this study if they had follow-up angiogram using catheter selected angiography at least twice. All subjected were followed up from 12 months to over 30 months. Of 120 patients, 123 aneurysms were enrolled. Patient data including age, sex, aneurysm size, neck size, procedural complication, kinds of stent, ISS associated symptom, ruptured state, location of ISS, degree of ISS, radiologic prognosis of ISS, follow-up period of time, and medical comorbidities such as hypertension, diabetes mellitus (DM), dyslipidemia, and smoking were collected.Statistical comparisons of group clinical characteristics were conducted for the total population.

Results

Among 123 casesof aneurysm, 22 cases (17.9%) of ISS were revealed on follow-up angiography. Multiple stenting was performed in three cases and intra-procedural rupture occurred in two cases. Most cases were asymptomatic and symptomatic stenosis was identified in only one case. Sixteen cases were ruptured aneurysm. Mild stenosis was observed in 11 cases. Moderate stenosis was found in eight cases and severe stenosis was identified in three cases. Mean timing of identification of ISS was 8.90 months. The most common type was proximal type. Most cases were improved or not changed on follow-up angiography. Only one case was aggravated from mild stenosis to occlusion of parent artery. Mean follow-up period was 44.3 months. We compared risk factors and characteristic between ISS group and non-ISS group using univariate analysis. Multiple stenting was performed for three cases (13.6%) of the ISS group and four cases (4.0%) of the non-ISS group, showing no statistical difference between the two groups (p=0.108). Additionally, the proportion of patients who had more than two risk factors among four medical risk factors (hypertension, DM, dyslipidemia, and smoking) was higher in the ISS group than that in the non-ISS group, the difference between the two was not statistically significant either (31.8% vs. 12.9%, p=0.05).

Conclusion

Clinical course and long-term prognosis of ISS might be benign. Most cases of ISS could be improved or not aggravated. Control of medical co-morbidity might be important. To the best of our knowledge, our study had more cases with longer follow-up period of time than other reports.

Efficacy of LVIS vs. Enterprise Stent for Endovascular Treatment of Medium-Sized Intracranial Aneurysms: A Hemodynamic Comparison Study

Background: We conducted a computational fluid dynamics (CFD) study and compared the treatment of medium-sized intracranial aneurysms with LVIS and Enterprise stent-assisted coil embolization (SACE) to determine the effects of hemodynamic changes caused by different stent and coil packing densities (PDs) in endovascular treatment.

Methods: We enrolled 87 consecutive patients, with 87 medium-sized intracranial aneurysms (≥7, ≤ 12 mm), who underwent LVIS or Enterprise SACE. Aneurysms treated with LVIS SACE were allocated to the LVIS group, and the remainder were allocated to the Enterprise group. CFD were performed to assess hemodynamic alterations between before treatment, after stent deployment, and after SACE.

Results: One aneurysm recanalized in the LVIS group (n = 42), and five recanalized in the Enterprise group (n = 45) (recanalization rate: 2.4 vs. 11.1%, respectively; P = 0.108). Higher complete obliteration rate (P = 0.069) was found in the LVIS group. Velocity at the neck plane showed a greater reduction ratio than velocity and WSS of the aneurysm in both groups after stent deployment, while velocity and WSS of the aneurysm showed a greater reduction ratio after coil placement. Further, there was a greater reduction in velocity at the neck plane (59.52 vs. 39.81%), aneurysmal velocity (88.46 vs. 69.45%), and wall shear stress (WSS) (85.45 vs. 69.49%) on the aneurysm in the LVIS group (P < 0.001 for all). Specifically, the reduction ratio of velocity at the neck plane showed significant difference between the groups in the multivariate analysis (P = 0.013).

Conclusions : LVIS SACE showed a lower recanalization for endovascular treatment of medium-sized intracranial aneurysms, and the greater hemodynamic alterations might be the key factors.

Neuroform Atlas stent deployment through the Barrel vascular reconstruction device for the treatment of a wide-necked acutely ruptured basilar aneurysm

BACKGROUND

The Barrel vascular reconstruction device is an electrolytically detachable laser-cut closed-cell stent used for neck reconstruction in wide-necked bifurcation aneurysms to support coiling without necessitating dual stent implantation. The purpose is to lower the metal-to-artery ratio and its inherent risk of thromboembolic complications of multiple stents.

CASE DESCRIPTION

A 53-year-old woman presenting with subarachnoid hemorrhage due to acutely ruptured basilar tip aneurysm underwent emergency endovascular embolization with the Barrel vascular reconstruction device. Since the stent did not cover the entire neck of the aneurysm, an Atlas stent was released in a Y configuration through the Barrel. The Neuroform Atlas correctly opened through the Barrel and allowed the complete exclusion of the aneurysm.

CONCLUSION

If necessary, releasing a Neuroform Atlas through a Barrel vascular reconstruction device is a feasible technique.

Small ruptured and unruptured complex cerebral aneurysms: Single center experience of low-profile visualized intraluminal support stent

Objectives:

Even though low-profile visualized intraluminal support (LVIS) device is used extensively currently and provide intraluminal support in complex cerebral aneurysm embolization, only few studies have reported its clinical results. This study presents the results of patients treated with LVIS.

Patients and methods:

Cerebral aneurysms with an undefined neck, fusiform shape, and blood blister-like aneurysms that were treated with LVIS between May 2017 and May 2019 were reviewed retrospectively.

Results:

Overall, 112 aneurysms in 104 patients were treated using LVIS, and 105 LVISs were placed. Of these, 101 aneurysms (90%) were small (< 10 mm) in size, 17 were fusiform aneurysms, and 3 were blood blister-like aneurysms. Overall, 39 patients suffered a subarachnoid hemorrhage and 65 had no bleeding history. 2 patients died of internal carotid artery (ICA) thrombosis, resulting in 1.9% mortality rate. Follow-up angiography was obtained in 68 patients (65%), and the complete obliteration rate was 98.5% in 6–12 months.

Conclusion:

The LVIS is a safe and effective treatment for small ruptured or unruptured complex intracranial aneurysms.

Treatment of Intracranial Aneurysms with Self-Expandable Braided Stents: A Systematic Review and Meta-Analysis

BACKGROUND

The safety and efficacy of treatment with self-expandable braided stents (LEO and LVIS) required further investigation.

PURPOSE

Our aim was to analyze the outcomes after treatment with braided stents.

DATA SOURCES

A systematic search of 3 databases was performed for studies published from 2006 to 2017.

STUDY SELECTION

According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies reporting patients treated with LEO or LVIS stents.

DATA ANALYSIS

Random-effects meta-analysis was used to pool the following: aneurysm occlusion rate, complications, and neurologic outcomes.

DATA SYNTHESIS

Thirty-five studies evaluating 1426 patients treated with braided stents were included in this meta-analysis. Successful stent delivery and complete aneurysm occlusion were 97% (1041/1095; 95% CI, 95%-98%) (I² = 44%) and 88.3% (1097/1256; 95% CI, 85%-91%) (I² = 72%), respectively. Overall, treatment-related complications were 7.4% (107/1317; 95% CI, 5%-9%) (I² = 44%). Ischemic/thromboembolic events (48/1324 = 2.4%; 95% CI, 1.5%-3.4%) (I² = 27%) and in-stent thrombosis (35/1324 = 1.5%; 95% CI, 0.6%-1.7%) (I² = 0%) were the most common complications. Treatment-related morbidity was 1.5% (30/1324; 95% CI, 0.9%-2%) and was comparable between the LEO and LVIS groups. Complication rates between the anterior (29/322 = 8.8%; 95% CI, 3.4%-12%) (I² = 41%) versus posterior circulation (10/84 = 10.5%; 95% CI, 4%-16%) (I² = 0%) and distal (30/303 = 8%; 95% CI, 4.5%-12%) (I² = 48%) versus proximal aneurysms (14/153 = 9%; 95% CI, 3%-13%) (I² = 46%) were comparable (P > .05).

LIMITATIONS

Limitations were selection and publication biases.

CONCLUSIONS

In this analysis, treatment with the LEO and LVIS stents was relatively safe and effective. The most common complications were periprocedural thromboembolisms and in-stent thrombosis. The rate of complications was comparable among anterior and posterior circulation aneurysms, as well as for proximal and distally located lesions.

Stent-assisted coil embolization of anterior communicating artery aneurysms using the LVIS Jr stent

BACKGROUND AND PURPOSE

This retrospective study evaluates the safety and mid-term and long-term effectiveness of stent-assisted coil embolization of anterior communicating artery (Acomm) aneurysms treated with the LVIS Jr stent.

MATERIALS AND METHODS

All patients treated with the LVIS Jr stent for Acomm aneurysms between June 2015 and March 2018 were included in the analysis. Details of the procedure's periprocedural adverse events, immediate aneurysm occlusion rates, and clinical and angiographic follow-up assessment were collected.

RESULTS

A total of 25 patients with 25 aneurysms were included. Eighteen aneurysms were found incidentally. Seven patients presented with seven ruptured aneurysms: Six were remotely ruptured and one acutely ruptured. Twenty-four patients were treated successfully and one technical failure is reported. The parent arteries measured 1.4 mm to 2.9 mm in diameter (mean, 2.3 mm). Intraprocedural thromboembolic complications occurred in two patients (8%) and an intraoperative aneurysm rupture in one patient (4%). Immediate complete aneurysm occlusion was noted in 18 out of 25 patients (72%). Clinical follow-up ranged from three months to 36 months (mean, 15.8 months) and the imaging follow-up ranged from two to 35 months (mean, 14.2 months). Complete aneurysm occlusion was achieved in 14 out of 20 patients (70%) at last angiographic follow-up. Of the two patients with in-stent thrombosis, one patient had an acutely ruptured aneurysm and the other patient was treated with an LVIS Jr stent in a Y configuration. Neurological morbidity and mortality rate were 0%.

CONCLUSIONS

Complex, wide-necked Acomm aneurysms can be effectively treated with stent-assisted embolization using LVIS Jr stents.

Y-configuration stenting for coiling of wide-neck bifurcation aneurysms using Low-profile Visualized Intraluminal Support Junior

Background

Little has been reported about the feasibility and durability of a Low-profile Visualized Intraluminal Support Junior (LVIS Jr) Y-stenting device for wide-neck bifurcation aneurysms.

Purpose

To evaluate the feasibility and durability of LVIS Jr Y-stenting for coiling of unruptured wide-neck bifurcation aneurysms.

Methods

We identified patients in whom LVIS Jr Y-stenting was attempted for unruptured wide-neck bifurcation aneurysms from a prospectively maintained registry of a referral hospital. Procedural success rate, treatment-related morbidity, and clinical and angiographic outcomes were retrospectively assessed.

Results

LVIS Jr Y-stenting was attempted for a total of 21 aneurysms in 21 patients (mean age 60±8.9 years; M:F=6:15): nine basilar artery, six anterior communicating artery, four middle cerebral artery, one internal carotid artery, and one vertebrobasilar fenestration aneurysms. The mean dome and neck size were 7.9±2.7 mm and 5.7±1.8 mm, respectively. All attempts were successful. Treatment-related morbidity occurred in one individual with a modified Rankin Scale (mRS) score of 2. Immediate postprocedural angiograms showed complete occlusion in 15 (71.4%) and neck remnant in 6 (28.6%) patients. All 21 patients had good outcomes (mRS score 0–2) for a mean of 12 months' follow-up (range 6–27 months); mRS score 0 in 20 patients and mRS score 2 in one patient, respectively. Follow-up imaging over a mean of 11 months (range 6–18 months) was available in 18 patients (85.7%). All aneurysms showed complete occlusion at follow-up.

Conclusions

LVIS Jr Y-stenting and coiling for wide-neck bifurcation aneurysms seems to be feasible with acceptable safety and to provide durable aneurysm occlusion for wide-neck bifurcation aneurysms.

A clinical comparison of Atlas and LVIS Jr stent-assisted aneurysm coiling

BACKGROUND

Case series have described the safety and efficacy of LVIS Jr and Atlas stent-assisted aneurysm coiling, but their comparative clinical performance has not yet been formally studied.

OBJECTIVE

To clinically compare LVIS Jr and Atlas stents, emphasizing comparative rates of technical success and complications.

METHODS

Our institutional endovascular database was queried for aneurysms treated by stent-assisted coiling with either the LVIS Jr or Atlas stents. Demographic data, aneurysm information, treatment technique, periprocedural and device-related complications, and initial and follow-up angiographic results were evaluated.

RESULTS

Thirty-seven patients underwent Atlas stent placement and 27 patients underwent LVIS Jr stent placement for aneurysm coiling. There was no significant difference in aneurysm location, size, coiling technique, and coil packing density between the two cohorts. The rate of initial Raymond 1 occlusion was significantly greater in the Atlas cohort (57% vs 41%, P=0.03). The rate of postoperative ischemic complications, both clinically apparent and as defined on postoperative MRI diffusion-weighted imaging, did not significantly differ between the two groups. Follow-up DSA demonstrated a significantly greater rate of Raymond 1 or 2 occlusion for the Atlas cohort (100% vs 81%, P=0.04), and a significantly lower rate of in-stent stenosis (0% vs 19%, P=0.04).

CONCLUSION

This institutional analysis demonstrates greater obliteration rates and lower in-stent stenosis rates for aneurysms treated via Atlas stent-assisted coiling as compared with those treated via LVIS Jr stent-assisted coiling.

Is Single Low-Profile Visualized Intraluminal Support (LVIS)-Assisted Coiling of Wide-Necked Ruptured Multiple Intracranial Aneurysms in One Stage Feasible?

OBJECTIVE

There is no previous reports available on stent-assisted coiling of ruptured multiple intracranial aneurysms using single Low-Profile Visualized Intraluminal Support (LVIS) in one stage. In the present study, we investigated the efficacy and feasibility of using single LVIS to bridge multiple intracranial aneurysms in one stage.

METHODS

From April 2014 to August 2016, 24 patients treated with single LVIS to bridge 2 aneurysms in one stage were reviewed. The aneurysm morphology, clinical outcome, angiographic results, progressive occlusion, recurrence, and procedure-related complications were analyzed retrospectively.

RESULTS

In the present study, middle term clinical outcome showed that 9 patients were had a modified Rankin Scale (mRS) score of 0, 11 patients had mRS 1, and 4 patients had mRS 2. A total of 20 patients (83.3%) achieved a good outcome, 4 patients (16.7%) had poor outcomes, and 7 of 18 patients (38.9%) displayed improved clinical neurologic status in long-term follow-up. Immediate angiographic results postprocedure showed Raymond Scale (RS) I in 33 aneurysms (68.8%), RS II in 11 aneurysms (22.9%), and RS III in 4 aneurysms (8.3%). The angiographic follow-up results showed RS I in 41 aneurysms (85.4%), RS II in 5 aneurysms (10.4%), and RS III in 2 aneurysms (4.2%). Of 15 incomplete occlusion aneurysms postprocedure, 10 aneurysms (66.7%) achieved to progressed occlusion on follow-up imaging, and no recanalization or mortality occurred in this group.

CONCLUSIONS

Single LVIS bridging wide-neck ruptured multiple intracranial aneurysms was effective and feasible in one stage. However, the procedure-related complications should be emphasized and long-term follow-up requires further evaluation.

LVIS Jr Device for Y-Stent-Assisted Coil Embolization of Wide-Neck Intracranial Aneurysms: A Multicenter Experience

Background and Purpose

Complex wide-neck intracranial aneurysms are challenging to treat. We report a multicenter experience using the LVIS Jr stent for "Y-stent"-assisted coiling embolization of wide-neck bifurcation aneurysms.

Methods

Seven centers provided retrospective data on patients who underwent Y-stenting. Technical complications, immediate posttreatment angiographic results, clinical outcomes, and imaging follow-up were assessed.

Results

Thirty patients/aneurysms were treated: 15 basilar tip, 8 middle cerebral artery, 4 anterior communicating artery, 1 pericallosal, and 2 posterior inferior cerebellar artery aneurysms. The mean aneurysm size was 11 mm and the mean dome-to-neck ratio was 1.3 mm. Twenty-four aneurysms were unruptured and treated electively, and 6 were acutely ruptured. Fifty-eight LVIS Jr stents were successfully deployed without any technical issue. One pro-cedural and transient in-stent thrombosis resolved with the intravenous infusion of a glycoprotein IIb/IIIa inhibitor. Five periprocedural complications (within 30 days) occurred: 2 periprocedural neurological complications (1 small temporal stroke that presented with transient aphasia and 1 posterior cerebral artery infarct) and 3 nonneurological periprocedural complications (2 retroperitoneal hematomas, and 1 patient developed a disseminated intravascular coagulopathy). One permanent complication (3.3%) directly related to Y-stenting was reported in the patient who suffered the posterior cerebral artery infarct. Immediate complete obliteration (Raymond-Roy Occlusion Classification [RROC] I-II) was achieved in 26 cases (89.6%). Twenty-four patients had clinical and imaging follow-up (mean 5.2 months). Complete angiographic occlusion (RROC I-II) was observed in 23 patients (96%). A good functional outcome with a modified Rankin Scale score ≤2 was achieved in 26 cases.

Conclusions

In this multicenter case series, Y-stent-assisted coiling of wide-neck aneurysms with the LVIS Jr device was feasible and relatively safe. Follow-up imaging demonstrated very low recanalization rates.

LVIS Jr. stent for treatment of intracranial aneurysms with parent vessel diameter of 2.5 mm or less

Background and purpose This retrospective study evaluates the safety, effectiveness, and long-term clinical and angiographic follow-up of intracranial aneurysms treated with the Low-Profile Visualized Intraluminal Support Junior (LVIS Jr.) stent and parent vessels of diameter equal to or less than 2.5 mm. Materials and methods We included all patients treated with the LVIS Jr. stent in aneurysms with small parent vessel diameter between March 2015 and July 2017. Periprocedural adverse events, immediate aneurysm occlusion rates, and clinical and angiographic follow-up are reported. Results A total of 35 patients with 35 aneurysms were included. Ten aneurysms were ruptured (28.6%) and 25 were unruptured (71.4%). The parent arteries measured 0.9 mm to 2.5 mm in diameter (mean, 2.2 mm). Intra-procedural thromboembolic complications occurred in four patients (11.4%) and there was an intraoperative aneurysm rupture in one patient (2.8%). Immediate complete aneurysm occlusion was noted in 21 out of 35 patients (60%). Clinical follow-up ranged between one and 25 months (mean, 10.5 months) and magnetic resonance angiography follow-up ranged between four and 24 months (mean, 10.4 months). Complete aneurysm occlusion was achieved in 21 out of 29 patients (72.4%) at last angiographic follow-up (mean, 9.4 months; range four to 23 months). In-stent stenosis occurred in one out of 29 patients (3.4%), who was asymptomatic. Of the four patients with in-stent thrombosis, three patients were treated with "Y configuration" (two patients with middle cerebral artery aneurysms and one patient with an anterior communicating artery aneurysm). Mortality rate was 0%. Neurological morbidity was 2.9%. Conclusions Stenting with the LVIS Jr. stent allowed us to treat complex intracranial aneurysms with parent vessel diameter of 2.5 mm or less with an acceptable safety profile.