Stent-Assisted Coiling of Wide-Neck Intracranial Aneurysms Using Low-Profile LEO Baby Stents: Initial and Midterm Results

Single Neuroform Atlas stent: a reliable approach for treating complex wide-neck bifurcated aneurysms

Background

Treating wide-neck bifurcated cerebral aneurysms (WNBAs) using various techniques and new devices has shown favorable outcomes. However, endovascular coiling can be technically challenging when the aneurysm neck is incorporated into the parent vessel. Furthermore, although recent research has reported favorable outcomes of Neuroform Atlas stent (NAS)-assisted coiling, broad inclusion criteria have hampered precise evaluations of their effectiveness and safety for treating complex WNBAs. Therefore, this study evaluated whether the use of a single NAS is a safe and effective approach for treating complex WNBAs.

Methods

We treated 76 complex WNBAs (unruptured, n = 49; ruptured, n = 27) using single NAS-assisted coil embolization and retrospectively analyzed the clinical and angiographic outcomes.

Results

In a cohort of 68 patients (mean age, 58.3 ± 11.6 years; males n = 20, 29.4%; females, n = 48, 70.6%), 76 stents were successfully delivered to the target aneurysms, yielding a technical success rate of 98.6%. Complete occlusion was evident in 59 (77.6%) of 76 aneurysms, with neck remnants found in 16 (21.1%) and partial occlusion in 1 (1.3%). Treatment-related morbidities comprised one branch occlusion and one parenchymal hemorrhage. However, no new neurological symptoms of unruptured aneurysms were evident at discharge. The outcomes of 20 of the 27 ruptured aneurysms were favorable (Glasgow Outcome Scale scores of 4 or 5) at the final follow-up assessment (mean 12.2 [6-29] months), except for one initial subarachnoid hemorrhage. Post-treatment angiography revealed complete occlusion in 89.1%, neck remnants in 7.8%, and incomplete occlusion in 3.1% of the aneurysms. Approximately 88.2% of the patients were assessed at least once by follow-up diagnostic or magnetic resonance angiography (mean, 12.5 ± 4.3 [range, 6-29] months), with five (7.8%) minor and two (3.1%) major recurrences.

Conclusion

A single NAS is safe and effective for treating WNBAs incorporated into parent vessels.

Appraisal of the Flow Diversion Effect Provided by Braided Intracranial Stents

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

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.

Periprocedural thromboembolic complications of LEO baby stent in endovascular treatment of intracranial aneurysms: Experience in 149 patients

OBJECTIVE

To report periprocedural thromboembolic complications of LEO Baby stent-assisted coiling of wide-necked intracranial aneurysms and to analyze the possible influencing factors.

METHODS

We retrospectively identified 149 patients with aneurysms who underwent LEO Baby stent-assisted embolization between October 2018 and March 2022. Clinical and radiographic data of patients were reviewed to determine whether a thromboembolic event had occurred. Multivariate logistic analysis was performed to identify significant factors associated with thromboembolic events.

RESULTS

Successful stent deployment of the stent was achieved in all patients in the target artery. There were 66 patients (44.3%) with acutely ruptured aneurysms and 83 patients (55.7%) with unruptured aneurysms. Fourteen (9.4%, 95% confidence interval: 4.7%-14.1%) patients were confirmed to have developed a thromboembolic event, including nine patients with acute intraoperative thrombosis and five patients with postoperative thromboembolic events. The rate of thromboembolic events was 6.0% (5/83) in patients with unruptured aneurysms and 13.6% (9/66) in patients with acutely ruptured aneurysms. There was a trend toward an increased rate of thromboembolic events in patients with acute ruptured aneurysms (p = 0.087). Thromboembolic events were significantly associated with the parent-artery diameter (p = 0.010).

CONCLUSIONS

Our study demonstrates a low rate of thromboembolic complications in unruptured aneurysms treated with LEO Baby stent. Thromboembolic events appear to be more common in ruptured aneurysms. A small diameter of the parent artery is associated with an increased risk of thromboembolic complications, and more relevant studies are still needed.

The Safety and Efficacy of Leo Stents with Coiling or Alone for Anterior Cerebral Artery Aneurysms

INTRODUCTION

Treatment of anterior cerebral artery (ACA) aneurysms is still not well established. The Leo stent with blood flow direction is a retrievable stent for intracranial aneurysms, whereas it needs to be studied clearly in patients with ACA aneurysms.

METHODS

Consecutive patients with ACA aneurysms were retrospectively enrolled in three neurosurgical centers between January 2016 and October 2021. The data on demographics, aneurysm characteristics, symptom resolution, and postoperative course were collected and analyzed. The aneurysm occlusion status was appraised by Raymond-Ray Occlusion Class (RROC).

RESULTS

A total of 57 patients with ACA aneurysms were included in our study. Immediate postprocedural angiograms showed that 20 aneurysms (35.1%) were in complete occlusion (RROC 1), 26 aneurysms (45.6%) were in near-complete occlusion (RROC 2), 11 aneurysms (19.3%) were in incomplete occlusion (RROC 3). The angiographic follow-up found that the rate of complete occlusion increased to 57.9%, and near-completion and incomplete occlusion dropped to 29.8% and 12.3%, respectively. The angiographic result of the last follow-up improved significantly (Z=- 2.805, P=0.005). Univariate analysis indicated that distal location of aneurysms (Z=4.538, P=0.033) and ruptured aneurysms (χ2=.6120, P=0.032) were potential risk factors for intra-parent artery narrowing. Furthermore, multivariate logistic regression analysis found that A3 aneurysms (95% CI 1.427~32.744, P=0.016) are the key risk factor for intra-parent artery narrowing.

CONCLUSIONS

The Leo stent is safe and effective for aneurysms located in ACA circulations. The overall occlusion degree improved during follow-up. A distal, small artery was the risk factor for intra-parent artery narrowing.

Long-term results of wide-necked intracranial bifurcation aneurysms treated with stent-assisted coiling using low-profile acandis acclino stents

PURPOSE

Little data exists on endovascular treatment of complex intracranial aneurysms with the Acandis Acclino low-profile self-expanding closed-cell stent systems and is mainly limited to short- or midterm results. We report our long-term, single-centre experience with three generations of Acclino stents treating complex intracranial aneurysms.

METHODS

62 wide-necked intracranial aneurysms were treated electively using 88 Acclino stent systems. Single stent-assisted coiling was the preferred treatment in 38 cases and the kissing-Y stenting technique in 24 cases. We analysed demographic data and long-term follow-up results.

RESULTS

All stents were successfully deployed with immediate complete (Raymond Roy occlusion classification, RROC I) or near-complete occlusion (RROC II) achieved in 93,5%. Follow-up was available in 55 cases with a mean follow-up of 36 months (range 9-80 months). Long-term RROC I or II was achieved in 49 cases (89,1%). Three cases of stable residual aneurysmal filling were observed (5,5%). Seven aneurysms (12,7%) demonstrated a worsening on follow-up leading either to a neck remnant (4 cases, 7,3%) or to an aneurysm recurrence (3 cases, 5,5%). One recurrent aneurysm was retreated with coilembolization (1,8%). The directly procedural-related complication rate was 4,8%. Seven cases of clinically silent in-stent stenosis (12,7%; morbidity n = 0) were detected on long-term follow-up, six of them using the kissing-Y stenting technique.

CONCLUSION

Endovascular treatment of various intracranial aneurysms using the Acandis Acclino stent systems is safe and efficient with high aneurysm occlusion rates combined with low complication rates on long-term follow-up. Overall, rates of in-stent stenosis are low but may depend on the treatment technique (single stent-assisted coiling versus kissing-Y stenting with coiling).

A comparison of Atlas and Leo Baby stents-assisted coiling of intracranial aneurysms with small parent vessels

Some studies have reported the efficacy and safety of the Atlas stent and the Leo Baby stent-assisted coiling (SAC) of intracranial aneurysms arising from small cerebral vessels. The authors aimed to compare the clinical performance of the Atlas and the Leo Baby stents in small parent arteries.

METHODS AND MATERIALS

Between January 2019 and November 2022, 56 patients at our centre were treated using either Atlas or Leo Baby SAC of intracranial aneurysms arising from small parent vessels (<2 mm). The clinical and angiographic imaging data of the two cohorts were retrospectively collected and comparatively analyzed.

RESULTS

A total of 56 patients were included in this study. Thirty-two patients were treated with the Atlas SAC, and 24 patients were treated with the Leo Baby SAC. The mean age of the Atlas stent cohort was older, and the mean aneurysm size was smaller than the Leo Baby stent. The immediate complete occlusion rate was 68.6% in the Atlas stent cohort and 62.5% in the Leo Baby stent cohort. The mean angiographic follow-up time for Atlas stent cohort was 8.9±2.5 months, and the final aneurysm complete occlusion rate was 81.0%. The mean follow-up time for Leo Baby stent cohort was 18.9±6.0 months, and the final aneurysm complete occlusion rate was 83.3%.

CONCLUSIONS

At the final follow-up, the Atlas or the Leo baby stent SAC of intracranial aneurysms with small parent vessels resulted in favourable angiographic results and clinical outcomes, with a low rate of associated complications.

Treatment of broad-based intracranial aneurysms with the LVIS EVO stent: a retrospective observational study at two centers with short- and medium-term follow-up

The use of stents is well established in the treatment of broad-based intracranial aneurysms. The aim of this study is to report on safety, feasibility and midterm follow-up of the new LVIS EVO braided stent for the treatment of cerebral aneurysms. All consecutive patients with intracranial aneurysms who were treated with the LVIS EVO stent in two high volume neurovascular centers were retrospectively enrolled in this observational study. Clinical and technical complications, angiographic outcome and clinical short-term and midterm results were evaluated. The study included 112 patients with 118 aneurysms. 94 patients presented with incidental aneurysms, 13 patients with acute SAH and 2 patients with acute cranial nerve palsy. For 100 aneurysms a jailing technique was used, re-crossing of the stent was performed in 3 cases. For the residual 15 cases the stent was placed as a bail-out or as a second step. Immediate complete occlusion was observed in 85 aneurysms (72%). Midterm follow-up was available for 84 patients with 86 aneurysms (72.9%). One stent showed asymptomatic complete occlusion on follow-up imaging, in all other cases no in-stent stenosis was observed. The rate of complete occlusion was 79.1% at 6 months and 82.2% at 12-18 months. Midterm follow-up data of this retrospective observational cohort of two neurovascular centers corroborates the safety profile of the LVIS EVO device for treatment of ruptured and unruptured intracranial aneurysms.

The Angiographic and Clinical Follow-up Outcomes of the Wide-Necked and Complex Intracranial Aneurysms Treated With LVIS EVO-Assisted Coiling

BACKGROUND

The Low Profile Visible Intraluminal Support EVO (LVIS EVO) is a self-expandable braided stent, which was recently introduced for the treatment of intracranial aneurysms. Full visibility of the stent and a relatively high metal coverage ratio are the unique features of the LVIS EVO.

OBJECTIVE

To assess the safety, efficacy, and midterm durability of LVIS EVO stent-assisted coiling for the treatment of wide-necked intracranial aneurysms.

METHODS

The endovascular databases were reviewed to identify patients treated with LVIS EVO-assisted coiling. The technical success and immediate clinical/angiographic outcomes were assessed. Periprocedural and delayed complications were evaluated. The follow-up angiographic/clinical outcomes were investigated. The preprocedural/follow-up neurological statuses were assessed with the modified Rankin Scale.

RESULTS

One hundred three aneurysms in 103 patients (63 females) with a mean age of 54.9 ± 11.3 years were included. The mean maximum sac diameter was 6.2 ± 2.9 mm. The procedural technical success rate was 100%. Immediate postprocedural angiography showed complete occlusion in 77.7%. The mean duration of the angiographic follow-up was 8.8 ± 3.6 months. Follow-up angiography showed complete aneurysm occlusion in 89% of the 82 patients with angiographic follow-up. Recanalization was observed in 7.3% of 82 patients. Two patients (2.4%) required retreatment. In addition, 8.7% of the patients had at least 1 complication, and 2.9% of the patients developed a permanent morbidity. All patients had mRS scores ≤2.

CONCLUSION

The results of this study demonstrate that SAC with LVIS EVO is a relatively safe, efficient, and durable treatment for wide-necked and complex intracranial aneurysms.

Evaluation of short- and long-term results of Y-stent-assisted coiling with Leo stents in endovascular treatment of wide-necked intracranial bifurcation aneurysms

PURPOSE

This study aimed to evaluate the feasibility, safety, and efficacy of Y-stent-assisted coiling (Y-SAC) using LEO Baby® stents in treating of bifurcation aneurysms.

METHODS

Patients who underwent Y-SAC using a braided stent (LEO Baby®, Montmorency, France) for wide-necked intracranial aneurysms between 2009 and 2019 and whose radiological and clinical follow-up data for at least 6 months could be obtained were evaluated. Data were obtained from patient records and analyzed retrospectively.

RESULTS

We evaluated 111 patients with a mean age of 56.0 ± 10.8 years (range, 25-88 years). Most of the aneurysms were detected incidentally. Three patients had ruptured aneurysms. LEO Baby deployment and coiling were successful in all patients. Immediate aneurysm occlusion rates were determined as modified Raymond-Roy classification (mRRC) I 95.5% (n = 106), mRRC II 3.6% (n = 4), mRRC IIIa 0.9% (n = 1). In the sixth month, aneurysm occlusion rates were found to be complete and nearly complete in all patients (mRRC I 94.6%, n = 105 and mRRC II 4.5%; n = 5, respectively). Follow-up data of 91 patients for > 2 years were obtained. Of these, 88 had MRRCI obstruction and 3 had MRRC II obstruction. The overall complication rate was 4.8%, and one patient died during the post-procedural follow-up.

CONCLUSION

The long-term follow-up results of Y-stenting with LEO Baby revealed that it provides stable closure of the aneurysm sac while preserving the main arterial structures. Therefore, it is a safe, durable, and effective method for treating wide-necked and complex bifurcation aneurysms.

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.

Endovascular Treatment of Ruptured Blood Blister-like Aneurysms Using the LVIS EVO Stents

Blood blister-like aneurysms (BBAs) are rare cerebrovascular lesions that face serious challenges in surgical as well as endovascular treatment. In this paper, we present our experience in treating BBAs using the LVIS EVO stents. A total of 10 patients (mean age of 56.1 years) with 13 BBAs, who were admitted to our university hospital between April 2020 and November 2021 with a subarachnoid hemorrhage (SAH) due to aneurysm rupture, were treated using the LVIS EVO stents. Treatment of the BBAs consisted of stent-assisted coiling in four patients and stenting in six patients. The aneurysms were located within ICA (84.6%), VA (7.7%), and MCA (7.7%). Placement of the LVIS EVO stents was successful in all patients. No technical complications were observed. One in-stent thrombotic event occurred during the procedure. MRA for one-year follow-up was performed in nine patients. One patient died (Hunt and Hess Grade IV). LVIS EVO stents may be a beneficial treatment option for BBAs, as they provide high occlusion rates. However, the long-term efficacy remains uncertain.

Endovascular Coiling of Fenestrated Vertebrobasilar Cerebral Aneurysms

Fenestrated vertebrobasilar junction aneurysms are uncommon vascular lesions. Surgical intervention remains extremely challenging due to the deep location and complex anatomy with adjacent cranial nerves and perforator vessels. Endovascular approach is safer and generally accepted as the primary treatment method. Optimal angiographic projections with three-dimensional reconstructions to guide microcatheter selection remain vital to successfully treating aneurysms with challenging fenestration anatomy. This report details the endovascular methods in two cases of fenestrated vertebrobasilar junction aneurysms with different coiling techniques.

Flow diversion effect of the leo braided stent for aneurysms in the posterior and distal anterior circulations: A multicenter cohort study

Background and purpose

The treatment of aneurysms located in the posterior and distal anterior circulations remains a challenge. Leo stents with a flow diversion (FD) effect may be a potential option, which needs to be clearly studied.

Methods

From January 2016 to October 2021, 133 patients with 145 aneurysms in the posterior and distal anterior circulations, treated with Leo stents, were retrospectively analyzed in three neurosurgical centers. Data on demographic information, aneurysm characteristics, procedural outcomes, postoperative course, and aneurysm occlusion were retrospectively analyzed.

Results

After immediate surgery, 90 aneurysms (60.1%) were in complete occlusion [Raymond-Ray Occlusion Class (RROC) 1 and O'Kelly Marotta (OKM) grade D], 29 aneurysms (20%) in good occlusion (RROC 2 and OKM grade C), 17.9% in incomplete occlusion (RROC 3a or OKM grade B), and no aneurysms in invalid occlusion (RROC 3b and OKM grade A). A total of 112 patients with 117 aneurysms received angiographic follow-up (mean 11.4 months), and the degree of occlusion showed a significant improvement (Z = 3.900, p < 0.001). The complete occlusion rate increased to 84.6% (99/117), while good and incomplete occlusion decreased to 6.8% (8/117) and 8.6% (10/117), respectively. A total of 14 cases (10.5%) presented narrowing of the parent artery, and nine cases (6.8%) had injured side branches. Cerebral hemorrhage occurred in four patients (3.0%), and symptomatic ischemic infarction occurred in six patients (4.5%). The final permanent morbidity (mCS ≥3) and mortality were 2.8% (3/133) and 0.8% (1/133), respectively. For 82 aneurysms treated by stent-assisted with coiling (SAC), large-sized, ruptured aneurysms (χ² = 7.767, p = 0.005) occurred. For 63 aneurysms treated by LEO stent monotherapy (LSM), multiple aneurysms, fusiform aneurysms (χ² = 18.958, p < 0.01), and/or small-sized aneurysms (Z = −2.692, p = 0.007) occurred.

Conclusions

Leo stents are safe and effective for aneurysms located in the posterior and distal anterior circulations. The overall degree of occlusion improved during a follow-up because of the FD effect of Leo stents. Aneurysms in these areas should be treated with personalized measures.

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.

Effect of the Shelving Technique on the Outcome of Embolization in Intracranial Bifurcation Aneurysms

BACKGROUND AND PURPOSE

Stent bulging technique has been introduced as a technique that improves the outcome of aneurysm coiling. Our aim was to evaluate the utility of this technique, which involves the intentional herniation of stents into the bifurcation aneurysms during coiling.

MATERIALS AND METHODS

Unruptured bifurcation aneurysms treated by stent-assisted coiling using a single type of low-profile braided (LEO Baby) stent between November 2012 and October 2018 were retrospectively evaluated. The clinical (age and sex) and morphologic characteristics (aneurysm size, neck size, proximal/distal diameters of the stented artery, incorporation of the origins of the side branches to the aneurysm neck, and bifurcation angle) and response to antiplatelet therapy were evaluated.

RESULTS

Sixty-one patients (29 men, 47.5%; mean age, 55.95 [SD, 12.33] years) with 66 aneurysms were included. There were 36 aneurysms in group A (treated with the stent bulging technique) and 30 aneurysms in group B (treated by classic stent-assisted coiling). There was no significant difference in the patient and aneurysm characteristics in the groups except for the larger size and wider neck of the aneurysms in group A (P = .02 and P = .04, respectively). At the mean follow-up of 27.30 (SD, 17.45) months, there was no significant difference in the complication rate, the occlusion status, and the early and long-term occlusion rates between the groups. The stent bulging technique did not predict total occlusion (Raymond-Roy I) at the final imaging follow-up.

CONCLUSIONS

The stent bulging technique enables the coiling of larger, wide-neck aneurysms; however, we did not observe an added flow-diversion effect with the stent bulging technique compared with conventional stent-assisted coiling. We, therefore, suggest that bifurcation aneurysms should be coiled as densely and as safely as possible using this technique.

Safety, Efficacy, and Durability of Stent-Assisted Coiling Treatment of M2 (Insular) Segment MCA Aneurysms

BACKGROUND AND PURPOSE

Most distal MCA aneurysms are located within the insular segment, which lies between the limen insulae and circular sulcus. However, experience is limited in the microsurgical and endovascular management of insular segment MCA aneurysms. In this multicenter retrospective case series, we aimed to investigate the safety, efficacy, and durability of stent-assisted coiling for treatment of insular segment MCA aneurysms.

MATERIALS AND METHODS

A retrospective review was performed to identify patients with insular MCA aneurysms that were treated with stent-assisted coiling. The technical success of the procedures and the initial and follow-up clinical and angiographic outcomes were assessed. Periprocedural and delayed complications were reviewed.

RESULTS

Twenty-seven aneurysms in 27 patients with a mean age of 53.3 (SD,11.3) years were included. The mean size of the aneurysms was 6.3 (SD 2.6) mm. Endovascular procedures were successfully performed in all patients. Immediate postprocedural angiography revealed complete aneurysm occlusions in 81.5%. Periprocedural complications developed in 7.4% without causing permanent morbidity. A delayed thromboembolic complication resulted in a minor permanent morbidity in 1 patient (3.7%). There was no mortality. The mean duration of angiographic follow-up was 19.5 (SD, 9.8)  months. The last follow-up examinations showed complete occlusion in 92.6%. During the follow-up period, none of the treated aneurysms showed recanalization.

CONCLUSIONS

The results of this study demonstrate that stent-assisted coiling with a low-profile self-expandable stent is a feasible and relatively safe technique for endovascular treatment of insular segment complex MCA aneurysms. Additionally, it provides an effective and durable treatment for insular MCA aneurysms.

Low-profile LEO baby stents using dual stenting technique in treating complex intracranial aneurysms located in small artery: Initial and mid-term outcome

BACKGROUND

Endovascular treatment of complex intracranial aneurysms (IAs) was challenging. Our retrospective study aimed to assess the efficacy and safety of LEO Baby stents using the dual stenting technique for complex IAs.

METHODS

Clinical and angiographic data of 15 IAs located in small arteries treated by LEO Baby stents in our neurosurgical center were retrospectively collected and analyzed between April 2019 to January 2021.

RESULTS

15 patients received dual stent-assisted coiling procedures and the stent configurations include 7 cases of T- configuration, 5 cases of parallel- configuration, 2 cases of Y- configuration, and 1case of X- configuration. 11 patients received dual stents deployment with only LEO Baby stents and 4 patients received LEO Baby stent combined with LVIS stent. Immediate postprocedural results showed Raymond I in 4 patients (26.7%), Raymond II in 5 patients (33.3%), and Raymond III in 6 patients (40.0%). One patient (6.7%) was confirmed with an ischemic complication during the procedure. All 15 patients (100%) received clinical follow-up ranging between 6 and 28 months. An mRS score of 0-2 was reached in all patients. 13 patients (86.7%) received angiographic clinical follow-up ranging between 6 and 20 months. The results revealed that Raymond I was achieved in 10 patients (76.9%) and Raymond II was achieved in 3 patients (23.1%). One patient (7.7%) in 6 months after the procedure was confirmed with asymptomatic in-stent stenosis.

CONCLUSION

This preliminary study suggests that dual stents deployment of LEO Baby stents was a feasible strategy for the treatment of complex IAs located in the small arteries.

Y-stent-assisted coiling with Neuroform Atlas stents for wide-necked intracranial bifurcation aneurysms: A preliminary report

Objective

To report our experience on Neuroform Atlas Y-stenting for coiling of unruptured wide-neck bifurcation aneurysms.

Methods

From March 2018 to January 2021, we treated 473 aneurysms in 436 patients with coil embolization, of which 15 cases with wide-necked bifurcation aneurysms were treated by Y-stent-assisted coiling with two Neuroform Atlas stents. We retrospectively reviewed the characteristics of patients and aneurysms, procedure-related complications, radiographic results, and clinical outcomes.

Results

All 15 cases using Neuroform Atlas Y-stenting were successful. Patients included 6 men and 9 women with a mean age ± standard deviation of 56.4±6.6 years. The mean dome and neck sizes were 6.4±3.1 mm and 4.7±1.8 mm, respectively. Immediate post-procedural angiograms showed complete occlusion in 46.7%, neck remnant in 13.3%, and incomplete occlusion in 40% of cases. No treatment-related morbidity or mortality occurred in any patients. All patients had good clinical outcomes (Glasgow Outcome Score 5) at both discharge and during a mean 12.3-month (range 1-28 months) follow-up. All aneurysms showed improved or stable occlusion on follow-up imaging. Further, the latest follow-up angiography showed complete occlusion in 73.3%, neck remnant in 6.7%, and incomplete occlusion in 20%.

Conclusions

Y-stent-assisted coiling with Neuroform Atlas stents might be a feasible and safe option for wide-necked bifurcation aneurysms.

Multi-centric European post-market follow-up study of the Neuroform Atlas Stent System: primary results

BACKGROUND

Few prospective series have described the safety and effectiveness of the Neuroform Atlas Stent System. We aimed to investigate the efficacy and safety of the device in patients treated for unruptured aneurysm.

METHODS

ATLAS EU PMCF is a consecutive, prospective, multicentric study that included patients with unruptured saccular aneurysm of all sizes. Follow-up visits were scheduled at 3-6 months and 12-16 months with digital subtraction angiography (DSA) or MRI imaging follow-up as per the site standard of care. The primary efficacy endpoint was adequate aneurysm occlusion (Raymond Roy occlusion grade I and II) on 12 month angiography. The primary safety endpoint was any major stroke or ipsilateral stroke or neurological death within 12 months.

RESULTS

Of the 106 patients consented, 105 were treated with at least one Neuroform Atlas stent. There was a failed implantation attempt in 1 patient, 85 patients received lateral stenting, and 19 patients received Y-stenting. Mean aneurysm neck size was 4.2 mm (range 1.9-33 mm). Adequate occlusion was observed in 95.1% immediately after the procedure and in 98.9% of cases at 1 year DSA follow-up. Overall, 1.0% (1/102; 95% CI 0.0% to 5.3%) of patients experienced a primary safety endpoint of major stroke. Three minor strokes resulted in a modified Rankin Scale score of 2.

CONCLUSIONS

In this multicentric, prospective study, stent-assisted coiling of medium size unruptured aneurysms with the Neuroform Atlas stent resulted in a favorable rate of satisfactory occlusion. In our findings, the use of the Y-stenting technique was associated with increased rates of procedural complications.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT02783339.

Safety and Efficacy of Stent-Assisted Coiling of Unruptured Intracranial Aneurysms Using Low-Profile Stents in Small Parent Arteries

BACKGROUND AND PURPOSE

Stent-assisted coiling of intracranial aneurysms arising from small vessels (≤ 2.0 mm) is a common procedure. However, data regarding its treatment outcomes are scarce. This study evaluated the clinical and radiologic outcomes of stent-assisted coiling using low-profile stents for aneurysms of small parent arteries.

MATERIALS AND METHODS

From November 2015 to October 2020, sixty-four patients with 66 aneurysms arising from parent arteries of ≤2.0 mm were treated with stent-assisted coiling using a Low-Profile Visualized Intraluminal Support Junior (LVIS Jr) or the Neuroform Atlas stent in a single institution. The clinical and radiologic data were retrospectively reviewed, and the risk factors for procedure-related complications were evaluated.

RESULTS

The LVIS Jr and Neuroform Atlas stents were used in 22 (33.3%) and 44 (66.7%) cases, respectively. Technical success was achieved in 66 cases (100%). Immediate postprocedural aneurysm occlusion grades assessed by the Raymond-Roy occlusion classification were I (57.6%), II (19.7%), and III (22.7%), respectively. Procedure-related complications occurred in 10 cases (15.2%), with 8 thromboembolic complications (12.1%) and 2 hemorrhagic complications (3.0%). Procedure-related morbidity was 4.5% without mortality. On multivariate analysis, current smoking (odds ratio = 7.1, P = .021) had a statistically significant effect on procedure-related complications.

CONCLUSIONS

Stent-assisted coiling of intracranial aneurysms with low-profile stents in small vessels (≤ 2.0 mm) had a 100% success rate and a 15.2% overall complication rate with 4.5% morbidity. Current smoking was a significant risk factor associated with procedure-related complications.

Endovascular Parent Artery Occlusion for Intracranial Aneurysms is a Viable, Cost-Effective Alternative: An Institutional Experience from Northeast India

Purpose.

Endovascular parent artery occlusion (PAO) may be an alternative approach for complex intracranial aneurysm with potentially life-threatening complications. Moreover, the long-term follow-up of the PAO for an intracranial aneurysm is reported sparingly, limited to the case series. It is therefore important to carry out more research on long-term follow-up of the implication of PAO of intracranial aneurysm. The aim of the study was to analyses our experience of PAO for intracranial aneurysms with emphasis on long-term follow-up.

Materials and Methods.

The data of patients treated with PAO for intracranial aneurysms were reviewed. The outcome was evaluated based on aneurysmal occlusion on immediate angiography, follow-up magnetic resonance angiography (MRA), and complications. The modified Rankin score (mRS) was used to evaluate the functional outcome during the last follow-up. The mean, range, and standard deviation were reported for other variables – the patient’s age, number, and percentage.

Results.

Endovascular treatment was performed in 178 patients including PAO in 18 patients. Of these 18 (eighteen) patients, there were 13 dissecting aneurysms, 4 mycotic aneurysms, and one traumatic aneurysm.

10 (ten) patients underwent PAO for proximal intracranial artery aneurysm and 8 (eight) patients for distal cerebral aneurysms. Complete occlusion of the aneurysm was achieved in 16patients (88.89%) and retrograde filling of the aneurysm was seen in 2 (11.11%) patients. One patient had intraprocedural coil migration resulting in a major infarct with an mRS of 2. Another patient (5.56%) had recanalization of the aneurysm and presented with rupture and intracranial hemorrhage with an mRS score of 4. The mRS of the other 16 patients (88.89%) was zero.

Conclusions.

Endovascular PAO for cerebral aneurysms was highly feasible and achieved complete occlusion. The morbidity and mortality rates were at the long-term follow-up also acceptable with negligible complications.

Endovascular Treatment of Intracranial Aneurysms Using the Novel Low Profile Visualized Intraluminal Support EVO Stent: Multicenter Early Feasibility Experience

Purpose

Low-profile, self-expandable stents have broadened therapeutic options available for definitive treatment of intracranial aneurysms. The novel Low-Profile Visualized Intraluminal Support (LVIS) EVO stent extends upon the success of its predecessor, the LVIS Jr stent, aiming to enable higher visibility and greater opening ability within a self-expandable and fully retrievable microstent system. In this study, we aim to report the early safety and feasibility experience with the LVIS EVO stent.

Materials and Methods

A multicenter, retrospective, observational study was conducted on patients who had intracranial aneurysms treated with the LVIS EVO stent across 3 Australian neurovascular centers between February 2020 and September 2020. Short-term technical and clinical outcomes were evaluated.

Results

A total of 22 LVIS EVO stents were successfully implanted to treat 15 aneurysms (3 ruptured, 12 unruptured) in 15 patients. Aneurysms ranged from 2 mm to 35 mm in dome height. The LVIS EVO stent was used for stent-assisted coiling in 11 patients and flow diversion in 4 patients. There were no device-related procedural complications. There were 2 cases of peri-procedural symptomatic thromboembolic complications and no procedure-related mortality. At early radiological follow up, 10 patients had complete occlusion, 4 patients had small neck remnants, and 1 patient who was managed with flow diversion had a residual aneurysm.

Conclusion

Early experience with the LVIS EVO stent demonstrated safety and feasibility for stent-assisted coiling as well as flow diversion for intracranial aneurysms. In this heterogeneous cohort, including ruptured, complex, and large aneurysms, all cases were technically successful.

Treatment of recurrent and residual aneurysms with the low-profile Acandis Acclino stent: Multi-center review of 19 patients

OBJECTIVE

To evaluate the safety and efficacy of the low-profile Acandis Acclino microstent for embolization of recurrent and residual intracranial aneurysms.

METHODS

Consecutive patients treated with the Acclino for aneurysm remnants at three German neurovascular centers were enrolled. The technical success, complications, angiographic and clinical outcome were investigated.

RESULTS

Nineteen patients (median age: 53 years) with 19 aneurysm remnants (median size: 5 mm, anterior circulation: 14) were included. Initial aneurysm treatment consisted of stand-alone coiling in 14 cases, stent-assisted coiling in 4 and clipping in 1. Acclino stent-assisted coil embolization was performed technically successfully in all patients. Morbidity occurred in one patient (5.3%) due to aneurysm perforation. At the angiographic follow-up with a median follow-up duration of 21 months (range: 5-37 months), complete occlusion was obtained in 76.9%. The retreatment rate was 7.7%.

CONCLUSIONS

Retreatment of aneurysm remnants with the Acclino microstent was associated with high aneurysm occlusion rates and acceptable morbidity. Further studies will be necessary to draw a definite conclusion.

Knowledge framework and emerging trends in intracranial aneurysm magnetic resonance angiography: a scientometric analysis from 2004 to 2020

Background

As magnetic resonance angiography (MRA) has been increasingly used in the follow-up of intracranial aneurysms (IAs) as a non-invasive technique, the knowledge framework and areas of research interest in intracranial aneurysms magnetic resonance angiography (IAMRA) change approximately every 10 years. However, few studies have quantitatively analyzed the published literature in this field. In the present study, we used scientometrics to survey the knowledge field, development trends, and research focus of IAMRA with the aim of providing a reference for further study.

Methods

We collected articles on IAMRA published from 2004 (Jan 1, 2004) to 2020 (May 24, 2020). Web of Science Core Collection databases (WoSCCd) including the Science Citation Index Expanded were searched. An experienced staff member from the Department of Radiology at Southern Medical University, assisted in screening articles for relevant articles. We used ArcGIS (a mapping and location analytics platform) to perform geographic visualization. Excel 2016 was used to analyze the literature data, including number of publications, impact factor (IF), and publication year. CiteSpace V was used to conduct a series of literature feature clustering, including author co-citation analysis, reference co-citation analysis (RCA), and burst keywords analysis.

Results

A total of 1,272 articles on IAMRA published between 2004 and 2020 were included. Of 257 journals, American Journal of Neuroradiology (IF 2018: 3.256) published the most IAMRA articles (109 publications, 8.57%), followed by Journal of Neurosurgery (IF 2018: 4.131, 51 publications, 4.16%), and Neuroradiology (IF 2018: 2.504, 51 publications, 4.01%). Of 56 countries, the USA published the most, with 347 articles [27.28%, IF: 3.14 (average IF of all journals in the country)], followed by Japan (242 articles, 19.03%, IF: 2.38), Germany (135 articles, 10.61%, IF: 3.21), and China (101 articles, 7.94%, IF: 2.86). A total of 1387 institutions published articles, with the Mayo Clinic publishing the most (33 articles, 2.59%), followed by Shanghai Jiao Tong University (25 article, 1.97%), Seoul National University (23 articles, 1.81%), and University Medical Center Utrecht (19 articles, 1.49%). Of 399 authors, Rinkel ranked first with 19 articles, followed by Li MH (18 articles), Uchino A (15 articles), and Saito N (13 articles). Cluster RCA showed that the first cluster was "#0 growth", followed by "#1 Guglielmi detachable coils". Timeline views showed that the time span of "#0 growth" was the closest to today. The modularity value was 0.6971, and the mean silhouette value was 0.5477. According to the burst keyword analysis, "risk factors associated to rupture" was the topic with the strongest burst since 2017. Studies conducted in several countries suggested that age is inversely related to the risk of rupture, which implies the importance of MRA follow-up for patients of different age.

Conclusions

From 2004 to 2020, the number of published IAMRA-related articles gradually increased. The USA and Western Europe lead in the field, with a concentration of cutting-edge talents and high-level scientific research institutions. A synthesis of the clustering results of RCA and burst keyword analysis indicated that unruptured IA growth, stent-assisted coil embolization, and risk factors associated to rupture were the current hotspots in IAMRA research.

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.

Endovascular Treatment of Intracranial Aneurysms

Traditionally, surgical clipping was the only available treatment modality for intracranial aneurysms. However, in the last few decades, the endovascular therapy of intracranial aneurysms (IAs) has seen a tremendous evolution and development. From coiling to flow diversion and flow disruptor devices, endovascular treatment modalities have increased in number and received broader indications throughout the years. In this review article, the treatment modalities for the endovascular management of IAs are presented, emphasizing newer devices and technologies.

Periprocedural Safety and Feasibility of the New LVIS EVO Device for Stent-Assisted Coiling of Intracranial Aneurysms: An Observational Multicenter Study

BACKGROUND AND PURPOSE

Stent-assisted treatment techniques can be an effective treatment option for intracranial aneurysms. The aim of this study was to evaluate the periprocedural feasibility and safety of the new LVIS EVO stent for the treatment of intracranial aneurysms.

MATERIALS AND METHODS

Patients with intracranial aneurysms treated with the LVIS EVO in 11 European neurovascular centers were retrospectively reviewed. Patient and aneurysm characteristics, procedural parameters, immediate grade of occlusion, and technical and clinical complications were assessed.

RESULTS

Fifty-seven patients with 59 aneurysms were treated with the LVIS EVO device; 57.6% of the aneurysms were incidental; 15.3% were acutely ruptured; 15.3% were recanalized or residual aneurysms; and 11.9% were treated for symptoms other than acute hemorrhage. The most frequent aneurysm locations were the middle cerebral artery (25.4%) and the anterior communicating artery (22.0%). The rate of immediate successful deployment was 93.2%. In 6.8% (n = 4) of cases, additional in-stent angioplasty was needed. The immediate complete occlusion rate was 54.2%, while there was a residual aneurysm in 35.6% and a residual neck in 10.2%. Periprocedural technical complications occurred in 7/59 treatments (11.9%; the most frequent technical complication [n = 3] was thrombus formation), which all resolved completely without clinical sequelae. Postprocedural neurologic complications occurred after 4/59 treatments (6.8%; 2 transient ischemic attacks, 1 minor stroke, 1 major stroke), of which only 1 persistent complication was directly related to the procedure (minor stroke in the vascular territory distal to the stent).

CONCLUSIONS

The LVIS EVO stent is a safe, feasible device for the treatment of intracranial aneurysms.

Initial Experience with LVIS EVO Stents for the Treatment of Intracranial Aneurysms

Background: Over the years, a variety of intracranial stents have been developed, which has expanded the therapy options available for cerebral aneurysms. The Low profile visible intraluminal support (LVIS) EVO stents are new devices, which officially appeared on the market in 2020. The purpose of the study is to report the initial technical and clinical experience with the new stent in the treatment of intracranial aneurysms. Materials and Methods: Between February and September 2020, 30 patients with 35 intracranial aneurysms (29 unruptured and 6 ruptured) were treated using the LVIS EVO stent in our department. The aneurysms were located within internal carotid artery (ICA) (42.9%), middle cerebral artery (MCA) (31.4%), anterior communicating artery (AComA) (11.4%), basilar artery (BA) (11.4%) and anterior cerebral artery (ACA) (2.9%). Stent-assisted coil embolization was performed in all cases. Results: All stents were deployed successfully in the desired position. Immediate complete occlusion of the treated aneurysms, described as Raymond–Roy occlusion classification (RROC) class 1, was achieved in all cases. No technical complications were observed. One thromboembolic complication occurred in the group of unruptured aneurysms and one patient died due to cerebral edema from aneurysms rupture group. Conclusion: In our observation, the showed a satisfactory safety profile LVIS EVO stents seem to be very flexible, can be safely maneuvered and deployed in tortuous vessels. They showed a good initial occlusion rate when used for treating intracranial aneurysms with SAC (stent-assisted coiling).

Safety and Efficacy of the Neuroform Atlas Stent for Treatment of Intracranial Aneurysms : A Systematic Review and Meta-Analysis

OBJECTIVE

The Neuroform Atlas (Stryker Neurovascular, Fremont, CA, USA) is a low-profile laser cut self-expanding nitinol stent designed to provide coil support and wall apposition during aneurysm embolisation. In this study, we performed a meta-analysis of outcomes after treatment with the Neuroform Atlas stent for the purpose of coil embolisation.

METHODS

The primary objectives of this meta-analysis were to define the safety (treatment-related complications, neurologic outcomes, mortality rate) and the efficacy (aneurysm occlusion rate) of the treatment of intracranial aneurysms with the Neuroform Atlas stent. A systematic review and meta-analysis was performed by searching PubMed, EMBASE, and the Cochrane CENTRAL Library for all published studies on the treatment of intracranial aneurysms with the Neuroform Atlas device up to 6 April 2020. The review was prepared in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 14 studies were analysed (577 patients with 593 intracranial aneurysms). The mean age was 58.2 years and 35.6% were male. Technical success of the procedure was 100%. RROC1/RROC2 (Raymond-Roy occlusion classification (RROC) 1/2) (total occlusion/neck remnant) at a mean follow-up of 8.9 months was achieved in 94.8%. RROC3 was 4.9%. All-cause mortality was 1.8% and permanent residual neurological deficit or disability was 2.7%. Overall complications at follow-up were 6.2%.

CONCLUSION

Our analysis demonstrated good rates of occlusion at follow-up for aneurysms treated with the Atlas device at follow-up. The safety profile appears similar to other low-profile intracranial stents.

Initial Experience of Coil Embolization for Unruptured Intracranial Aneurysm Combined with Neuroform Atlas and Undersized Flexible Coils

Objective

Intraprocedural rupture (IPR) is a rare complication that can occur during endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs). However, it leads to high morbidity and mortality rates. Others have showed that coil flexibility is a risk factor for IPR. Neuroform Atlas (NA) stents can be deployed with 0.0165-inch microcatheters to enable stent assisted coiling (SAC) with a high likelihood. Undersized flexible coils can be inserted initially during SAC. This study aimed to determine whether SAC using NA and highly flexible coils for UIAs can be conducted without IPR.

Methods

We retrospectively analyzed nine consecutive patients (mean age, 73.2 years; female, n = 6) who underwent SAC for UIAs combined with NA stents and undersized flexible coils between January 2017 and December 2019. Two aneurysms were located at the internal carotid artery (ICA), and one each was located at the ICA-posterior communicating, anterior communicating, middle cerebral, vertebral, vertebra-posterior inferior cerebral and basilar arteries. The mean size of the aneurysms was 4.6 (range, 3.1-8.6) mm. SAC proceeded using the jailing technique. All coils were selected from among the most flexible coils available. We retrospectively assessed technical success rates, aneurysm occlusion at final digital subtraction angiography (DSA), volume embolization ratios (VERs), rates of IPR and symptomatic stroke within 30 days, angiographic findings of aneurysm occlusion at 3 months post-procedure and late adverse events (frequency of aneurysmal rupture, ipsilateral ischemic stroke, and retreated targeted aneurysms).

Results

The technical success rate was 100%. Complete occlusion (CO) was immediate in 8 (89%) patients and a neck remnant persisted in 1 (11%). No IPR or symptomatic stroke developed within 30 days. During a mean follow-up period of 11.8 months, CO persisted in 8 (89%) patients. No late adverse events occurred.

Conclusion

The early clinical and angiographic findings of SAC for UIAs combined with an NA stent and undersized flexible coils were favorable for this series.

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.

Evaluation of the Accero Stent for Stent-Assisted Coiling of Unruptured Wide-Necked Intracranial Aneurysm Treatment with Short-Term Follow-Up

BACKGROUND

Stent-assisted coiling is an effective method of treating intracranial aneurysms. The aim of the study was to assess the safety and efficacy of the new Accero stent for the treatment of intracranial aneurysms.

MATERIALS AND METHODS

It was a retrospective, single-center study. Eighteen unruptured intracranial aneurysms were treated using the stent-assisted coiling method with the Accero stent. Patient demographics, aneurysm characteristics, procedural parameters, grade of occlusion, complications, and clinical results were analyzed. Follow-up magnetic resonance (MR) was performed 6 months after intervention.

RESULTS

Seventeen patients with 18 incidental unruptured aneurysms were electively treated with coiling and the Accero stent. The aneurysms were located on internal carotid artery (ICA), middle cerebral artery (MCA) and basilar artery (BA). All stents were deployed successfully. Immediate complete occlusion rate Raymond-Roy occlusion classification (RROC) class I was achieved in 13 cases and class II in 4 cases. Complications occurred in 2/17 treatments and included guidewire stent perforation with subarachnoid hemorrhage (SAH) and stent deformation. Vascular spasm in the subarachnoid hemorrhage (SAH) patient subsided before discharge. Ninety days after intervention, the modified Rankin Scale (mRS) value was 0. RROC class I was observed in 88.23% of cases in follow-up.

CONCLUSION

The Accero stent provides excellent support for coil mass. It constitutes an efficacious device with good initial occlusion rate for treating wide-necked unruptured intracranial aneurysms.

Early experience treating intracranial aneurysms using Accero: a novel, fully visible, low profile braided stent with platinum-nitinol composite wire technology

BACKGROUND

Accero is an innovative, fully visible, self-expanding braided stent with platinum-nitinol composite wire technology, produced by Acandis.

OBJECTIVE

To assess the technical success and safety of this new stent by evaluating the intraprocedural behavior and complication rate, and the short-term follow-up results.

METHODS

Forty-one consecutive patients suitable for stent-assisted coiling were selected for the use of Accero in an 11-month period. Clinical, procedural, and angiographic data, as well as 30-day morbidity, were recorded. The angiographic results, clinical follow-up at 30 days, and early imaging follow-up at 3 or 6 months were analyzed, when available.

RESULTS

Forty-one aneurysms were treated with stent-assisted coiling. All cases were elective, of which 19 were previously untreated aneurysms and 22 were recurrent aneurysms. Aneurysm location was anterior communicating artery complex (16), basilar (12 cases), middle cerebral artery bifurcation (9 cases), and internal cerebral artery (4 cases). The stent was successfully deployed and aneurysm occlusion with coils achieved in 100% of our patients. One case of on table in-stent thrombosis occurred, which resolved after administration of glycoprotein IIB/IIIA inhibitor, with no clinical consequence, and one case of postoperative hematoma at the arteriotomy site, which was managed conservatively. On early follow-up, available for 37 patients, the complete occlusion rate was 76%, with only two recurrences needing further treatment. Satisfactory aneurysm occlusion was therefore achieved in 95% of cases.

CONCLUSION

Stent-assisted coiling with the Accero braided stent proved safe and effective.

Multicenter Postmarket Analysis of the Neuroform Atlas Stent for Stent-Assisted Coil Embolization of Intracranial Aneurysms

BACKGROUND AND PURPOSE

The Neuroform Atlas is a new microstent to assist coil embolization of intracranial aneurysms that recently gained FDA approval. We present a postmarket multicenter analysis of the Neuroform Atlas stent.

MATERIALS AND METHODS

On the basis of retrospective chart review from 11 academic centers, we analyzed patients treated with the Neuroform Atlas after FDA exemption from January 2018 to June 2019. Clinical and radiologic parameters included patient demographics, aneurysm characteristics, stent parameters, complications, and outcomes at discharge and last follow-up.

RESULTS

Overall, 128 aneurysms in 128 patients (median age, 62 years) were treated with 138 stents. Risk factors included smoking (59.4%), multiple aneurysms (27.3%), and family history of aneurysms (16.4%). Most patients were treated electively (93.7%), and 8 (6.3%) underwent treatment within 2 weeks of subarachnoid hemorrhage. Previous aneurysm treatment failure was present in 21% of cases. Wide-neck aneurysms (80.5%), small aneurysm size (<7 mm, 76.6%), and bifurcation aneurysm location (basilar apex, 28.9%; anterior communicating artery, 27.3%; and middle cerebral artery bifurcation, 12.5%) were common. A single stent was used in 92.2% of cases, and a single catheter for both stent placement and coiling was used in 59.4% of cases. Technical complications during stent deployment occurred in 4.7% of cases; symptomatic thromboembolic stroke, in 2.3%; and symptomatic hemorrhage, in 0.8%. Favorable Raymond grades (Raymond-Roy occlusion classification) I and II were achieved in 82.9% at discharge and 89.5% at last follow-up. mRS ≤2 was determined in 96.9% of patients at last follow-up. The immediate Raymond-Roy occlusion classification grade correlated with aneurysm location (P < .0001) and rupture status during treatment (P = .03).

CONCLUSIONS

This multicenter analysis provides a real-world safety and efficacy profile for the treatment of intracranial aneurysms with the Neuroform Atlas stent.

Stent-Assisted Coiling Using Leo+ Baby Stent : Immediate and Mid-Term Results

Background

Stent-assisted coiling is well-established for treatment of cerebral aneurysms. The technique enables treatment of wide-neck, bifurcation and recurrent aneurysms with high packing rates. While described in extenso for laser cut stents, the results of patients treated with the Leo+ Baby (Balt, Montmorency, France) braided microstent are presented.

Material and Methods

Patients were included if treated with a Leo+ Baby and with digital subtraction angiography (DSA) follow-up available of at least 6 months. Data were evaluated for successful deployment, aneurysm occlusion according to the modified Raymond-Roy classification (MRRC), stent patency and procedure-related morbidity and mortality.

Results

A total of 81 patients were included and Leo+ Baby deployment was successful in all cases. Coils were used in 80 cases. In 1 case 2 stents were used stent-in-stent without additional coiling. Initial aneurysm occlusion rates were MRRC_i1 51.9%, MRRC_i2 11.1%, MRRC_i3a 24.7% and MRRC_i3b 12.3%. Occlusion rates after 6 months were MRRC_6m1 78.9%, MRRC_6m2 3.9%, MRRC_6m3a 6.6% and MRRC_6m3b 10.5%. Procedure-related morbidity was 1 case of acute stent thrombosis successfully treated with tirofiban and 1 case with transient hemiparesis due to stent thrombosis after 4 months. There was 1 case of coil-associated subarachnoid hemorrhage (SAH) which caused prolonged hospitalization. No procedure-related mortality was observed.

Conclusion

The results confirm that stent-assisted coiling with the Leo+ Baby stent is safe and efficient for treatment of wide neck or recurrent cerebral aneurysms. Spontaneous progressive aneurysm occlusion over 6 months supports the theory of considerable flow-modulating effects of Leo+ Baby.

Single Center Experience in Stent-Assisted Coiling of Complex Intracranial Aneurysms Using Low-Profile Stents : The ACCLINO® Stent Versus the ACCLINO® Flex Stent

PURPOSE

The introduction of low-profile stent systems has broadened and facilitated the treatment of complex intracranial aneurysms. This retrospective case series study was conducted to assess and compare the clinical and angiographic outcomes of patients with complex intracranial aneurysms who were treated with ACCLINO® (AS) and ACCLINO® flex stents (AFS).

METHODS

In 85 patients (female 61; male 24) a total of 95 complex intracranial aneurysms, 71 (74.7%) in the anterior circulation and 24 (25.3%) in the posterior circulation were treated. Angiographic and clinical data, aneurysm characteristics and follow-up results were analyzed.

RESULTS

The AS was used in 47 cases (49.5%) and the AFS in 48 cases (50.5%). Initial angiography after the intervention showed a complete occlusion in 52.6% (Raymond-Roy occlusion classification [RROC] 1), a neck remnant in 38.9% (RROC 2) and an incomplete occlusion in 8.4% (RROC 3). Follow-up (AS: 25.2 ± 15.4 months; AFS: 9.6 ± 8.0 months) revealed an occlusion rate of 70.5% (RROC 1), 27.4% (RROC 2) and 2.1% (RROC 3). There was no statistically significant difference between the initial (p = 0.484) and the follow-up occlusion rate (p = 0.284) when comparing the two devices. Recoiling was performed in 8 cases (8.4%). The overall complication rate was 9.5% with 5 strokes (5.3%), 2 hemorrhages (2.1%), 1 in-stent stenosis (1.1%), 1 stent occlusion (1.1%) and 2 stent thromboses (2.1%). There was no procedure-related mortality.

CONCLUSION

Using the ACCLINO® and ACCLINO® flex stent system is a feasible and effective procedure with an acceptable safety profile. Initial and follow-up angiographic results were satisfactory.

Low-Profile Laser-Cut Stents for Endovascular Treatment of Intracranial Aneurysms : Incidence, Clinical Presentation and Risk Factors of Thromboembolic Events

PURPOSE

Low-profile intracranial stents are characterized by a miniaturized design that enables deployment via a 0.0165″ or 0.017″ internal diameter microcatheter, which is typically intended for coil delivery. This study analyzed the incidence, clinical relevance and risk factors of thromboembolic events (TEE) occurring during low-profile stent-assisted coiling of intracranial aneurysms.

METHODS

This was a retrospective, multicenter analysis of consecutive patients who underwent stent-assisted aneurysm coiling (SAC) with the laser-cut Acandis Acclino and Neuroform Atlas stents. The study evaluated the incidence of symptomatic and asymptomatic TEEs and the impact on functional outcome. Risk factors for TEEs were determined by univariate and bivariate logistic regression analyses.

RESULTS

Among 131 procedures (mean patient age 56.5 ± 12.8 years, mean aneurysm size: 6.7 ± 3.9 mm) TEEs occurred in 14 cases (10.7%) of which 2 patients (1.5%) developed ischemic stroke, while the remaining TEEs remained asymptomatic. Multivariate analysis revealed Y‑stenting as potential risk factor for TEEs (odds ratio: 3.9, 95% confidence interval: 1.0-16.5; p = 0.08).

CONCLUSION

The use of SAC with low-profile intracranial stents is associated with a favorable safety profile; however, Y‑stenting may carry an increased risk of TEEs, which needs to be considered during treatment planning.

Clinical Safety and Effectiveness of Stent-Assisted Coil Embolization with Neuroform Atlas Stent in Intracranial Aneurysm

Objective

Stent-assisted coil embolization (SAC) is commonly used for treating wide-neck intracranial aneurysms. In this study, we aimed to assess the clinical safety and efficacy of the NeuroForm Atlas Stent during SAC of intracranial aneurysms.

Methods

We retrospectively analyzed data from patients with ruptured and unruptured cerebral aneurysms, who underwent SAC using the NeuroForm Atlas between February 2018 and July 2018. Favorable clinical outcomes and degree of aneurysm occlusion were defined as a modified Rankin scale score of ≤2 and a Raymond-Roy occlusion classification (RROC) class I/II during the immediate postoperative period and at the 6-month follow-up, respectively.

Results

Thirty-one consecutive patients with 33 cases, including 11 ruptured and 22 unruptured cases were treated via NeuroForm Atlas SAC. Among the 22 unruptured cases with 24 unruptured aneurysms had favorable clinical outcome. Complete occlusion (RROC I) was achieved in 16 aneurysms (66.7%), while neck remnants (RROC II) were observed in six aneurysms (25%). Among the 11 patients with ruptured aneurysms, two died due to re-bleeding and diabetic ketoacidosis. In ruptured cases, RROC I was observed in eight (72.7%) and RROC II was observed in three cases (27.3%). At the 6-month follow-up, no clinical events were observed in the 22 unruptured cases. In the ruptured nine cases, five patients recovered without neurologic deficits, while four experienced unfavorable outcomes at 6 months. Of the 29 aneurysms examined via angiography at the 6-month follow-up, 19 (65.5%) were RROC I, eight (27.6%) were RROC II and two (6.9%) were RROC III. There were no procedure-related hemorrhagic complications.

Conclusion

In this study, we found that stent-assisted coil embolization with NeuroForm Atlas stent may be safe and effective in the treatment of wide-neck intracranial aneurysms. NeuroForm Atlas SAC is feasible for the treatment of both ruptured and unruptured wide-neck aneurysms.

Y-Stent-Assisted Coiling With Low-Profile Neuroform Atlas Stents for Endovascular Treatment of Wide-Necked Complex Intracranial Bifurcation Aneurysms

BACKGROUND

Y-stent-assisted coiling is one of the eligible techniques for the treatment of complex bifurcation aneurysms. In majority of previous literature, Y-stenting has been performed using stents that could be delivered through large profile microcatheters that are often difficult to manipulate during navigation through sharply angled side branches. Attempts to navigate with these large profile catheters might cause serious complications during Y-stenting procedure.

OBJECTIVE

To investigate the safety, feasibility, and efficacy of Y-stent-assisted coiling procedure with Neuroform Atlas stents for the treatment of complex bifurcation aneurysms; Neuroform Atlas is a recently introduced open-cell stent that can be delivered though low-profile microcatheters.

METHODS

We identified the patients with intracranial bifurcation aneurysms treated by Y-stent-assisted coiling procedure with Neuroform Atlas stents. We assessed the immediate postoperative and follow-up clinical and angiographic outcomes. We also investigated the periprocedural and delayed complications.

RESULTS

A total of 30 aneurysms in 30 patients were included in the study. Y-stenting was successfully performed without any technical complications in all cases (100%). Immediate postprocedural angiography revealed total aneurysm occlusion in 83.3% of patients. The mean angiographic follow-up time was 11.8 mo. The last follow-ups showed complete occlusion in 93.3% of patients. There was no mortality in this study. A procedure-related complication developed in 6.7% and resulted in permanent morbidity in 3.3% of patients.

CONCLUSION

Neuroform Atlas stent combines the advantages of low-profile deployment microcatheters with an open-cell structure to achieve a successful Y-stenting procedure. Y-stent-assisted coiling with Neuroform Atlas stents provides a safe and effective endovascular treatment for wide-necked complex bifurcation aneurysms.

Long-term Angiographic Results of the Low-profile Acandis Acclino Stent for Treatment of Intracranial Aneurysms : A Multicenter Study

PURPOSE

The low-profile Acandis Acclino is a self-expandable nitinol microstent for stent-assisted coiling of intracranial aneurysms. This article reports long-term clinical and angiographic outcome in a multicenter setting.

METHODS

In this study 98 consecutive patients (mean age 55.4 ± 13.5 years) were treated with the Acclino for 98 aneurysms (28 unruptured, 20 recurrent, 50 ruptured) at 3 German tertiary care centers within a 6-year period. The technical success, complications, clinical outcome and angiographic results were retrospectively analyzed.

RESULTS

The technical success rate was 100% with immediate complete occlusion achieved in 89.8% of the patients. Among 65 patients (66.3%) available for a 6‑month follow-up, complete and near-complete occlusion rates were 92.3% and 98.5%, respectively. In 38 patients (38.8%) with long-term follow-up (mean: 21 months), complete and near-complete occlusion were achieved in 81.2% and 89.5%, respectively. Aneurysm recurrence between mid-term and long-term follow-up was observed in 14.3%. The retreatment rate was 11.3%. There were three thromboembolic events (3.1%), of which one resulted in ischemic stroke (1.0%). For unruptured aneurysms, the procedural and device-related morbidity rates were 2.1% and 0%, respectively.

CONCLUSION

In the present study, the Acclino was associated with a low risk of thromboembolic complications and high aneurysm occlusion rates at long-term follow-up. Due to incomplete angiographic follow-up in this series, prospective studies will be necessary to confirm the results.

Preliminary experience of stent-assisted coiling of wide-necked intracranial aneurysms with a single microcatheter

BACKGROUND

The purpose of this study was to report our preliminary experience of stent-assisted coiling (SAC) of wide-necked intracranial aneurysms with a single microcatheter in patients with parent arteries that were small-caliber, with stenosis, or a very tortuous course.

METHODS

Between March 2018 and December 2018, we treated 394 aneurysms in 359 patients with endovascular treatment. Among 197 aneurysms treated by SAC, there were 16 cases (all wide-necked unruptured aneurysms) treated by SAC with a single microcatheter and a Neuroform Atlas stent. Follow-up angiography was performed at 6 to 12 months after SAC, and clinical follow-up was performed from 6 to 12 months in all patients.

RESULTS

The reasons for SAC with a single 0.0165-in. microcatheter were small-caliber (n = 4), stenosis (n = 2), and very tortuous course (n = 10) of the parent arteries. There was no complication related to delivering or deploying the Neuroform Atlas stent as well as no failure of selecting aneurysm by cell-through technique. All patients had a modified Rankin score of 0 at discharge and at follow-up. Initial angiographic results showed six cases (37.5%) of complete occlusion. In follow-up angiographies, 12 cases (75.0%) achieved compete occlusion.

CONCLUSION

When performing SAC of wide-necked intracranial aneurysms in parent arteries with small-caliber, stenosis, or a very tortuous course, cell-through SAC using a single microcatheter and a Neuroform Atlas stent within a 5 Fr- (or smaller) guiding or intermediate catheter might be a useful option.

Feasibility and midterm outcomes of endovascular embolization for true posterior communicating artery aneurysms

PURPOSE

Endovascular treatment (EVT) of true posterior communicating artery (PcomA) aneurysms has been rarely reported. This study reports the outcomes on a single-center cohort with true PcomA aneurysms who underwent EVT.

METHODS

Between June 2011 and June 2017, clinical data from 42 patients with 43 true PcomA aneurysms who underwent EVT were retrieved from a prospectively maintained single-center database. Endovascular techniques, perioperative complications, clinical outcomes, and angiographic results were retrospectively evaluated.

RESULTS

All aneurysms were treated successfully. Treatment modalities included simple coiling in 30 aneurysms, balloon-assisted coiling in two, and stent-assisted coiling in 11 cases. Immediate angiograms showed complete occlusion in 23 aneurysms (53.5%), residual neck in 8 cases (18.6%), and residual sac in 12 (27.9%). No procedure-related complications or mortality were observed. Of the 34 aneurysms that underwent angiographic follow-up at an average duration of 7.1 months post-procedure, complete occlusion was achieved in 22 (64.7%), neck remnant in eight (23.5%), and residual sac in four (11.8%) aneurysms, respectively. Six aneurysms (18.2%) that underwent conventional coiling developed recanalization and required retreatment. Seven cases that received stent-assisted coiling did not develop recurrence. Clinical follow-up (mean, 24.3 months) of all patients demonstrated no neurologic deterioration or (re)bleeding.

CONCLUSION

EVT of the true PcomA aneurysm is a safe and feasible procedure but may be associated with recurrence in midterm follow-up, requiring close surveillance and potential retreatment.

Double stent assisted coiling of intracranial bifurcation aneurysms in Y and X configurations with the Neuroform ATLAS stent: immediate and mid term angiographic and clinical follow-up

Purpose

Self-expandable stents have broadened the spectrum of endovascular treatment of intracranial aneurysms. However, procedures involving double stenting in Y/X configurations carry a relatively high risk of procedural complications. The Neuroform ATLAS, the evolution of Neuroform EZ, is a nitinol self-expanding hybrid/open cell stent which can be delivered through a low profile 0.017 inch catheter. We present our experience in the treatment of intracranial aneurysms with this stent in Y and X configurations.

Materials and methods

We prospectively maintained a database from consecutive patients who underwent double stent assisted coiling with the Neuroform ATLAS, from July 2015 to February 2019. Clinical and angiographic results were analyzed.

Results

55 patients harboring 55 bifurcation aneurysms were treated with double stenting: 52 ‘Y’ configurations, 3 ‘X’ configurations. Deployment was successful in all cases. Post-treatment control angiography showed complete occlusion in 33 cases (60%), neck remnant in 8 cases (14.5%), and incomplete occlusion in 14 cases (25.4%). The overall symptomatic periprocedural complication rate was 12.7%. 38 aneurysms underwent follow-up (69%, mean duration 16 months): 33 aneurysms (87%) were completely occluded, 3 aneurysms (8%) had a neck remnant, and 2 aneurysms (5%) were incompletely occluded.

Conclusion

The Neuroform ATLAS is an effective device for treatment of bifurcation aneurysms, allowing good conformability, a high level of navigability, and easy mesh crossing to perform Y/X stenting procedures. The rate of procedural complications remains non-negligible, and an indication for a double stenting procedure should be carefully discussed in a multidisciplinary meeting.

In vitro investigation of chemical properties and biocompatibility of neurovascular braided implants

Braiding of Nitinol micro wires is an established technology for the manufacturing of fine-meshed neurovascular implants for tortuous vessel geometries. Electropolishing of wires before the braiding process has the potential to improve the in vitro behaviour in terms of thrombogenicity and endothelial cell proliferation. In this study, we present the first in vitro investigation of braided electropolished/blue oxide Nitinol samples in a blood flow loop, showing a significantly lower activation of the coagulation pathway (represented by the TAT III marker) and a tendency towards reduced platelet adhesion. Furthermore, we applied the same surface treatment on flat disks and measured protein adhesion as well as endothelial cell proliferation. We compared our results to non-electropolished samples with a native oxide surface. While platelet deposition was reduced on electropolished/blue oxide surface, a significant increase of endothelial cell seeding was observed. Investigation of inflammatory marker expression in endothelial cells provided divergent results depending on the marker tested, demanding closer investigation. Surface analysis using Auger electron spectroscopy revealed a thin layer mainly consisting of titanium oxynitride or titanium oxide + titanium nitride as a potential cause of the improved biological performance. Translated to the clinical field of intracranial aneurysm treatment, the improved biocompatibility has the potential to increase both safety (low thrombogenicity) and effectiveness (aneurysm neck reconstruction).