Intravascular stent and endovascular coil placement for a ruptured fusiform aneurysm of the basilar artery. Case report and review of the literature

The Management of Intracranial Aneurysms: Current Trends and Future Directions

Intracranial aneurysms represent a major global health burden. Rupture of an intracranial aneurysm is a catastrophic event. Without access to treatment, the fatality rate is 50% in the first 30 days. Over the last three decades, treatment approaches for intracranial aneurysms have changed dramatically. There have been improvements in the medical management of aneurysmal subarachnoid haemorrhage, and there has been an evolution of treatment strategies. Endovascular therapy is now the mainstay of the treatment of ruptured intracranial aneurysms based on robust randomised controlled trial data. There is now an expansion of treatment indications for unruptured intracranial aneurysms to prevent rupture with both microsurgical clipping and endovascular treatment. Both microsurgical and endovascular treatment modalities have evolved, in particular with the introduction of innovative endovascular treatment options including flow diversion and intra-saccular flow disruption. These novel therapies allow clinicians to treat more complex and previously untreatable aneurysms. We aim to review the evolution of treatment strategies for intracranial aneurysms over time, and discuss emerging technologies that could further improve treatment safety and functional outcomes for patients with an intracranial aneurysm.

Stent-assistant versus non-stent-assistant coiling for ruptured and unruptured intracranial aneurysms: A meta-analysis and systematic review

Background

Several different endovascular and non-invasive treatment methods are suggested for the various types of intracranial aneurysms including simple, balloon-assisted, and stent-assisted coiling (SAC). Previous studies investigated the safety and efficacy of SAC versus non-stent-assisted coiling (non-SAC) but the results were controversial. We aim to perform a systematic review and meta-analysis to compare the efficacy and safety of SAC with non-SAC technique in stratifying by the ruptured and unruptured aneurysms.

Methods

PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were searched in April 2022 for studies investigated the efficacy and safety of SAC versus non-SAC.

Results

Overall, 26 studies entered into our qualitative and quantitative synthesis. We found that there was overall lower recurrence rate in SAC versus non-SAC significant (RR: 0.43, 95%CI: 0.33, 0.53). Furthermore, the comparisons were significant in unruptured (RR: 0.63, 95%CI: 0.40, 0.86), ruptured (RR: 0.29, 95%CI), and combination aneurysms (RR: 0.42, 95%CI: 0.30, 0.54). Also, we found higher risk of intraprocedural rupture for SAC versus non-SAC in unruptured aneurysms (RR: 1.40, 95%CI: 1.31, 1.50). Investigating hemorrhagic events risk showed that there was significant difference in ruptured (RR: 1.73, 95%CI: 1.12, 2.34) and combination aneurysms (RR: 0.60, 95%CI: 0.37, 0.82). There was no significant difference in immediate occlusion rate, complete occlusion, and risk of ischemic events in our analysis.

Conclusion

Overall, our findings demonstrated that SAC may have higher efficacy in term of recurrence rate, but also may have a higher risk of complications in the treatment of intracranial aneurysms. As there are several factors affecting the outcomes and safety of these interventions, further RCTs controlled for multiple factors are required better guide the neurointerventionists choose the best strategy.

Single centre experience of stent-assisted coiling of wide-necked basilar tip aneurysms

OBJECTIVE

To report clinical and radiological follow-up outcomes of stent-assisted coiling of wide-necked basilar tip aneurysms and to evaluate the safety and efficacy of this treatment choice.

METHODS

A retrospective review was carried out of 19 patients with wide-necked basilar tip aneurysms in our institution between 2010 and 2020. The rates of perioperative complication, morbidity, mortality, imaging follow-up and re-treatment were analysed.

RESULTS

Our technical complication rate was 11% but did not result in treatment failure. The combined procedure related morbidity and mortality rate of the 19 patients who underwent stent assisted coiling was also 11%. 16 of 19 patients had undergone angiographic follow-up with a mean period of 32 months. 81% of patients with angiographic follow-up had a satisfactory occlusion (RROI or II) with 11% requiring re-treatment. Those requiring re-treatment were both treated with laser-cut stents; this is in contrast with no re-treatments required in the patients treated with braided stents.

CONCLUSION

Our report provides acceptable outcomes in wide-necked basilar termination aneurysms which are very challenging to treat. Aneurysms treated with braided stents had better efficacy outcomes than those with laser-cut stents.

ADVANCES IN KNOWLEDGE

Given the emergent and increasing utility of alternative endovascular techniques such as intrasaccular devices and flow diverters, real-world data are lacking on more conventional approaches such stent-assisted coiling, especially so in the posterior circulation. The associated relatively higher aneurysmal haemorrhagic risk in this location warrants further additional safety and efficacy data for this treatment approach, which this paper provides.

Stent-Assisted Coil Embolization Versus Flow-Diverting Stent in Unruptured Vertebral Artery Dissecting Aneurysms: Efficacy and Safety Comparison

BACKGROUND

Reconstructive strategies for unruptured vertebral artery dissecting aneurysms (VADAs) have increasingly relied on newly developed endovascular devices. However, their clinical performance metrics are seldom reported.

OBJECTIVE

To compare stent-assisted coil embolization (SACE) and flow-diverting stent (FDS) deployment as treatments for unruptured VADAs, focusing on efficacy and safety.

METHODS

A total of 72 VADAs were submitted to SACE (n = 48) or FDS (n = 24) between April 2009 and September 2021. We reviewed medical records and radiological data to assess efficacy and safety outcomes by method, building an inverse probability of treatment-weighted (IPTW) logistic regression model and conducting survival analyses.

RESULTS

Ultimately, 24 aneurysms (33.3%) showed signs of recanalization (major, 14; minor, 10) at 6-month follow-up. Initially determined 6-month rates of overall (SACE, 31.2%; FDS, 41.7%) and major (SACE, 20.8%; FDS, 16.7%) recanalization did not differ significantly by modality; but in the IPTW logistic regression model, adjusted for aneurysm morphology, major recanalization at 6 months was lower for the FDS (vs SACE) subset (odds ratio = 0.196; P = .027). Likewise, the cumulative rate of major recanalization was more favorable for the FDS (vs SACE) subset (hazard ratio = 0.291; P = .048) in IPTW Cox proportional hazards model adjusted for aneurysm morphology. Modality-based assessments of procedural and delayed complications were similar.

CONCLUSION

Both reconstructive VADA interventions are safe and effective by adjusting treatment modality depending on the angioanatomic configuration. However, follow-up data after treatment proved more favorable for FDS deployment than for SACE in limiting major recanalization. Case-controlled studies of more sizeable cohorts are needed for corroboration.

History of Neurointervention

In this review article, we aim to provide a summary of the discoveries and developments that were instrumental in the evolution of the Neurointerventional field. We begin with developments in the advent of Diagnostic Cerebral Angiography and progress to cerebral aneurysm treatment, embolization in AVMs and ischemic stroke treatment. In the process we discuss many persons who were key in the development and maturation of the field. A pivotal aspect to rapid growth in the field has been the multidisciplinary involvement of the different neuroscience specialties and therefore we close out our discussion with excitement about ongoing and future developments in the field with a focus on treatments in the non-cerebrovascular disease realm.

A review of the top 100 most influential articles on basilar artery aneurysms

Basilar artery aneurysms account for approximately 5% of all intracranial aneurysms. This bibliometric analysis summarizes the most-cited articles on basilar artery aneurysms and highlights the contributing articles to today's evidence-based practice. In the execution of this bibliometric-based review article, the Scopus database was used to perform a title-specific, keyword-based search for all publications until August 2022. The keyword "basilar artery aneurysm" or "basilar aneurysm" was used. Our results were arranged in descending order based on the article's citation count. The 100 most cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact Per Paper (SNIP), and Hirsch index. The keyword-based search showed that 699 articles were published between 1888 and 2022. The top 100 articles were published between 1961 and 2019. The top 100 most cited articles collected a total of 8869 citations with an average of 89 citations per paper. The rate of self-citations accounted for an average of 4.85% of the total number of citations. The bibliometric analysis provides a quantitative overview of how medical topics and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in basilar artery aneurysms by finding the top 100 most cited papers.

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.

Enterprise stents versus low-profile visualized intraluminal support stents for stent-assisted coiling of unruptured paraclinoid aneurysms

BACKGROUND

The microsurgical treatment of paraclinoid aneurysms can be challenging due to the anatomical structures that surround them.

OBJECTIVE

This study compared the clinical and angiographic outcomes of unruptured paraclinoid aneurysms treated with enterprise (EP) stents and low-profile visualized intraluminal support (LVIS) stents.

METHODS

A retrospective analysis of the clinical and radiological data from 133 patients with 139 unruptured paraclinoid aneurysms, who received an EP or an LVIS stent between January 2017 and June 2021 at Taizhou People's Hospital, was performed. Immediate postoperative and follow-up angiographic results were analyzed retrospectively using the Raymond-Roy occlusion classification (RROC). Any complications following the procedure and the patients' clinical outcomes were noted.

RESULTS

Enterprise stents were used for stent-assisted coiling in 64 patients with 68 aneurysms and LVIS stents were used in 69 patients with 71 aneurysms. Both groups exhibited an increase in the proportion of aneurysms meeting the criteria for RROC class I, but the LVIS group demonstrated a higher rate of aneurysms meeting the class I criteria compared with the EP group, both on immediate postoperative angiography (45.1% vs. 11.8%, p< 0.001) and on follow-up angiography (94.9% vs. 80.6%, p= 0.025). Procedure-related complications were experienced by 9.4% of patients in the EP group (one coil prolapse, two parent artery occlusions, and three thromboembolic events), and 8.7% of patients in the LVIS group (three stent-related thrombosis and three thromboembolic events). There were no statistically significant differences between the two groups in relation to perioperative complications (p= 0.746) or favorable clinical outcomes (p= 0.492).

CONCLUSION

A greater proportion of aneurysms in the LVIS group met the criteria for RROC class I compared with the EP group. There is no significant difference in procedural complications or clinical outcomes between EP and LVIS stents. Although no aneurysm recurrence was observed during the short follow-up period, continued monitoring is required.

A review of technological innovations leading to modern endovascular brain aneurysm treatment

Tools and techniques utilized in endovascular brain aneurysm treatment have undergone rapid evolution in recent decades. These technique and device-level innovations have allowed for treatment of highly complex intracranial aneurysms and improved patient outcomes. We review the major innovations within neurointervention that have led to the current state of brain aneurysm treatment.

Worldwide productivity and research trends of publications concerning stent application in acutely ruptured intracranial aneurysms: A bibliometric study

Background

Stenting is a common clinical practice to treat acutely ruptured intracranial aneurysm (RIA). Although multiple studies have demonstrated its long-term safety and effectiveness, there is currently a lack of bibliometric analysis on stent application in acutely RIA. This study sought to summarize the current status of research in this field and lay a foundation for further study.

Materials and methods

Related publications were searched in the Web of Science Core Collection (WoSCC) database. Data analysis and visualization were performed by R and CiteSpace software.

Results

A total of 275 publications published in English from 1997 to 2022 were included in this study. The growth of publications slowed down. The reference co-citation network identified 13 clusters with a significant network (Q = 0.7692) and convincing clustering (S = 0.9082). The research focus was acutely RIA and the application of stents during interventional procedures. The main trends of research were: (1) development of materials, and (2) safety of stent application in acutely RIA. The United States contributed the most articles, and Jianmin Liu was the most prolific author. Mayo Clinic was the leading institution in this field. Most articles were published in Interventional Neuroradiology.

Conclusions

This study analyzed the research trends, hotspots and frontiers of stent application in acutely RIA. It is our hope that the results obtained could provide useful information to researchers to get a clearer picture about their future research directions in this field.

Evolution and Revolution of Imaging Technologies in Neurosurgery

We understand only a small fraction of the events happening in our brains; therefore, despite all the progress made thus far, a whole array of questions remains. Nonetheless, neurosurgeons invented new tools to circumvent the challenges that had plagued their predecessors. With the manufacturing boom of the 20th century, technological innovations blossomed enabling the neuroscientific community to study and operate upon the living brain in finer detail and with greater precision while avoiding harm to the nervous system. The purpose of this chronological review is to 1) raise awareness among future neurosurgeons about the latest advances in the field, 2) become familiar with innovations such as augmented reality (AR) that should be included in education given their ready applicability in surgical training, and 3) be comfortable with customizing these technologies to real-life cases like in the case of mixed reality.

Current status and outlook of potential applications of biodegradable materials in cerebral vascular stents

The treatment of intracranial aneurysms (IAs) has undergone a very significant transformation in recent decades, and endovascular interventions have gradually become one of the most common treatments. As permanent metal stents can cause some degree of long-term damage to patients, biodegradable stent materials are emerging as attractive potential alternatives. By reviewing the current research status and the advantages and disadvantages of existing biodegradable biomaterials, this review expects to provide a valuable reference for subsequent research on biodegradable biomaterials.

The Safety and Efficacy of Flow Diversion versus Conventional Endovascular Treatment for Intracranial Aneurysms: A Meta-analysis of Real-world Cohort Studies from the Past 10 Years

BACKGROUND

Although the flow diverter has advantages in the treatment of intracranial aneurysms, pooled studies that directly compare it with conventional endovascular treatments are rare.

PURPOSE

Our aim was to compare the safety and efficacy of flow-diverter and conventional endovascular treatments in intracranial aneurysms.

DATA SOURCES

We performed a comprehensive search of the literature using PubMed, EMBASE, and the Cochrane Database.

STUDY SELECTION

We included only studies that directly compared the angiographic and clinical outcomes of flow-diverter and conventional endovascular treatments.

DATA ANALYSIS

Random effects or fixed effects meta-analysis was used to pool the cumulative rate of short- and long-term angiographic and clinical outcomes.

DATA SYNTHESIS

Eighteen studies with 1001 patients with flow diverters and 1133 patients with conventional endovascular treatments were included; 1015 and 1201 aneurysm procedures were performed, respectively. The flow-diverter group had aneurysms of a larger size (standard mean difference, 0.22; 95% CI, 0.03-0.41; P = .026). There was a higher risk of complications in the flow-diverter group compared with the conventional endovascular group (OR, 1.4; 95% CI, 1.01-1.96; P = .045) during procedures. The follow-up angiographic results of flow-diverter treatment indicated a higher rate of complete occlusion (OR, 2.55; 95% CI, 1.70-3.83; P < .001) and lower rates of recurrence (OR, 0.24; 95% CI, 0.12-0.46; P < .001) and retreatment (OR, 0.31; 95% CI, 0.21-0.47; P < .001).

LIMITATIONS

Limitations include a retrospective, observational design in some studies, high heterogeneity, and selection bias.

CONCLUSIONS

Compared with the conventional endovascular treatments, the placement of a flow diverter may lead to more procedure-related complications, but there is no difference in safety, and it is more effective in the long term.

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.

Non-visualizable stent-occlusion after treatment of a fusiform PCA-aneurysm-a case report

We report the case of a 17-year-old woman with extensive subarachnoidal hemorrhage due to a ruptured fusiform aneurysm of the right PCA (posterior cerebral artery). Endovascular treatment was successfully performed using a LVIS-EVO-Stent (Microvention Incorporation, Tustin, USA) as well as several coils. Short-term angiographic follow-up demonstrated extensive aneurysm progression and dilatation of the coil package, the stent could no longer be visualized and was not passable. Despite excellent distal vascular perfusion, a non-visible stent occlusion was suspected and subsequent occlusion of the patent artery was performed. We conclude that rapid progression of fusiform aneurysms after stent-assisted coiling may lead to expansion of the coil packages and non-assessability of the stent. Even with excellent distal perfusion, a stent-occlusion should be suspected in these cases. Therefore, we suggest short-term angiographic follow-up, especially after deploying multiple coil packages in fusiform aneurysms.

Comparison of Long-Term Angiographic Results of Wide-Necked Intracranial Aneurysms : Endovascular Treatment with Single-Microcatheter Coiling, Double-Microcatheter Coiling, and Stent-Assisted Coiling

Objective

Endovascular treatment of intracranial aneurysms is challenging in case of wide-necked aneurysms because coils are prone to herniate into the parent artery, causing thromboembolic events or vessel occlusion. This study aims to compare long-term angiographic results of wide-necked aneurysms treated by stent-assisted, double-microcatheter, or single-microcatheter groups.

Methods

Between January 2003 and October 2016, 108 aneurysms that were treated with endovascular coil embolization with a neck size wider than 4 mm and a follow-up period of more than 3 years were selected. We performed coil embolization with singlemicrocatheter, double-microcatheter, and stent-assisted techniques. Angiographic results were evaluated using the Raymond-Roy occlusion classification (RROC). All medical and angiographic records were reviewed retrospectively.

Results

Clinical and angiographic analyses were conducted in 108 wide-necked aneurysms. The immediate post-procedural results revealed RROC class I (complete occlusion) in 66 cases (61.1%), class II (residual neck) in 36 cases (33.3%), and class III (residual sac) in six cases (5.6%). The final follow-up results revealed class I in 48 cases (44.4%), class II in 49 cases (45.4%), and class III in 11 cases (10.2%). Of a total of 45 (41.6%) radiologic recurrences, there were 21 cases (19.4%) of major recurrence that required additional treatment, and 24 cases (22.2%) of minor recurrence. The final follow-up angiographic results showed statistically significant differences between the stent-assisted group and the others (p<0.01).

Conclusion

Long-term follow-up angiography demonstrated that the stent-assisted technique had a better complete occlusion rate than the other two techniques.

Flow-diverting device versus coil embolization for unruptured intracranial aneurysm: A meta-analysis

BACKGROUND

Both coil embolization (CE) and flow-diverting device (FDD) placement are widely used for treatment of intracranial aneurysms (IAs). The aim of this meta-analysis is to compare the relative clinical safety and efficacy of FDD and CE for the treatment of unruptured IAs.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched for relevant studies from the date of inception through April 2020. The primary endpoint for this meta-analysis was the 6-month rate of complete occlusion, while secondary endpoints included rates of retreatment, complications, and parental arterial patency.

RESULTS

This meta-analysis includes 8 studies, which included 839 total patients that underwent FDD and 2734 that underwent CE. FDD group exhibited a significantly higher pooled 6-month complete occlusion rate (P = .02). The subgroup analysis demonstrated that FDD treatment was associated with significantly higher pooled 6-month complete occlusion rates in patients with large or giant IAs (P < .00001), whereas no differences in 6-month complete occlusion rates were observed between the FDD and CE groups of patients with non-large/giant IAs (P = .83). The pooled retreatment (P = .16) and complication (P = .15) rates were comparable between 2 groups. The CE group exhibited significantly higher pooled parent artery patency rate (P = .01). The funnel plots did not reveal any evidence of publication bias.

CONCLUSIONS

FDDs can be used to effectively and safely treat large and giant IAs, achieving higher rates of complete occlusion than CE treatment. For non-large/giant IAs, we observed comparable efficacy between FDD and CE treatments.

The evolution of intracranial aneurysm treatment techniques and future directions

Treatment techniques and management guidelines for intracranial aneurysms (IAs) have been continually developing and this rapid development has altered treatment decision-making for clinicians. IAs are treated in one of two ways: surgical treatments such as microsurgical clipping with or without bypass techniques, and endovascular methods such as coiling, balloon- or stent-assisted coiling, or intravascular flow diversion and intrasaccular flow disruption. In certain cases, a single approach may be inadequate in completely resolving the IA and successful treatment requires a combination of microsurgical and endovascular techniques, such as in complex aneurysms. The treatment option should be considered based on factors such as age; past medical history; comorbidities; patient preference; aneurysm characteristics such as location, morphology, and size; and finally the operator’s experience. The purpose of this review is to provide practicing neurosurgeons with a summary of the techniques available, and to aid decision-making by highlighting ideal or less ideal cases for a given technique. Next, we illustrate the evolution of techniques to overcome the shortfalls of preceding techniques. At the outset, we emphasize that this decision-making process is dynamic and will be directed by current best scientific evidence, and future technological advances.

Bibliometric analysis of the top 100 most cited articles on the basilar artery

Background

The basilar artery (BA) is one of the most critical vessels that supply blood to the brain stem, cerebellum, and parts of the cerebral hemispheres. Many studies on the BA from neurobiological, clinical, and experimental perspectives exist. This bibliometric study was aimed at identifying the most-cited articles related to the BA in different disciplines.

Methods

A title-specific search was carried out using the Scopus database, and the top 100 most-cited articles were collected and analyzed. Article- and cytometric-based parameters were established for the literature review.

Results

The top 100 articles have an accumulative citation count of 13,595, with an average of 135.95 citations per paper. The publication dates range from 1946 to 2015, with the most productive years being those in the 1990s. Experimental studies are the most frequent category, followed by endovascular ones. The top-cited article has received a total of 435 citations, with 18.12 citations per year. The United States of America has contributed the most to the top 100 cited articles. The lead research institution was the University of Bern, and the most contributing journal was the Journal of Neurosurgery.

Conclusion

A bibliometric analysis of BA researches revealed landmark papers and trends over the years, such as on the introduction of endovascular management in basilar aneurysm and occlusion. The highly cited articles in multi-disciplinary areas related to the BA may help develop future novel ideas for research in the laboratory and translational fields.

Recent advances in stent-assisted coiling of cerebral aneurysms

INTRODUCTION

Stent-assisted coiling (SAC) of intracranial aneurysms paved the way for endovascular coiling of wide-neck and bifurcation aneurysms, improving rates of aneurysm obliteration and recurrence. In this review, we provide a comprehensive review of the most recent advances related to stent-assisted coiling of intracranial aneurysm.

AREAS COVERED

The authors have made an attempt to cover the inception, applications, and limitations of SAC of intracranial aneurysms. Special focus is given to 1) the current and recently introduced SAC techniques, 2) most recent advances in device technology, and 3) outcome data for the discussed techniques and devices. The authors also discuss the potential future direction of SAC.

EXPERT OPINION

technical refinements in the field of SAC should continue to focus on device development and addressing the limitations of SAC, namely aneurysm recurrence and need of antiplatelet agents. Although the recurrence rate of SAC has not been shown to be inferior to flow diverters, the use of intrasaccular and intravascular flow diverters are likely to expand in the future at the expense of SAC.

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.

'Railroad switch' technique for stent-assisted coil embolization of a wide-neck bifurcation intracranial aneurysm: technical note

Preservation of the posterior cerebral arteries during endovascular treatment of wide-neck basilar bifurcation aneurysms remains a technical challenge despite recent device innovations. We present a novel stent deployment technique, the 'railroad switch', to protect both posterior cerebral arteries during treatment of a recurrent basilar bifurcation aneurysm. Following asymmetric basilar-posterior cerebral artery stent deployment, favoring distal placement in a posterior cerebral artery, advancement of a jailed microcatheter will advance the proximal stent into the aneurysm, protecting both posterior cerebral arteries and the native basilar terminus. This novel maneuver offers interventionalists another application of commonly used intracranial stents for endovascular management of complex basilar bifurcation aneurysms.

Neurovascular devices for the treatment of intracranial aneurysms: emerging and future technologies

Introduction: Despite numerous advances in the endovascular treatment of intracranial aneurysms (IAs), treatment in cases of wide-neck, complex configurations or branching locations remains challenging. Apart from the paradigm shift introduced by flow diverters, several other devices have seen the light or are under development in order to address these challenges.Areas covered: We performed a review of the novel implantable endovascular devices which have been introduced for the treatment of IAs, from 1 January 2014 to 1 September 2019, excluding classic flow diverter and intracranial stent designs.Expert opinion: Alternative designs have been proposed for the treatment of IAs at branching positions, which do not jail the side branches, with or without flow diversion effect, most of which with good initial outcomes. Endosaccular devices have also been proposed, some of which with lower initial total occlusion rates. Alternative materials such as biopolymers have also been proposed and are under bench research. Despite the challenges in the exploitation of some of the new devices, most of them seem to provide solutions to some current technical shortcomings. The exploitation of the biological phenomena and the physical properties of the devices will allow us to expand the therapeutic armamentarium for more complex IA cases.

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.

Comparison of stent-assisted and no-stent coil embolization for safety and effectiveness in the treatment of ruptured intracranial aneurysms

OBJECTIVE

The safety of the stent-assisted coil embolization (SAC) technique for acutely ruptured aneurysms has not been established yet. SAC is believed to be associated with a high risk of thromboembolic and hemorrhagic complications in acute subarachnoid hemorrhage (SAH). The aim of this study was to evaluate the safety and efficacy of the SAC technique in the setting of acutely ruptured aneurysm.

METHODS

A total of 102 patients who received endovascular treatment for acute SAH between January 2011 and December 2017 were enrolled. The SAC technique was performed in 38 of these patients, whereas the no-stent coil embolization (NSC) technique was performed in 64. The safety and efficacy of the SAC technique in acute SAH was evaluated as compared with the NSC technique by retrospective analysis of radiological and clinical outcomes.

RESULTS

There were no significant differences in clinical or angiographic outcomes between the SAC and NSC techniques in patients with acute SAH. The rate of ventriculostomy-related hemorrhagic complications was higher in the SAC group than that in the NSC group (63.6% vs 12.5%; OR 12.25, 95% CI 1.78-83.94, p = 0.01). However, all these complications were asymptomatic and so small that they were only able to be diagnosed with imaging.

CONCLUSIONS

Ruptured wide-necked aneurysms could be effectively and safely treated with the SAC technique, which showed clinical and angiographic outcomes similar to those of the NSC technique. Hence, the SAC technique with dual-antiplatelet drugs may be a viable option even in acute SAH.

Safety and Efficacy of Stent-assisted Coiling in the Treatment of Unruptured Wide-necked Intracranial Aneurysms: A Single-center Experience

Introduction: Wide-necked intracranial aneurysms (IAs) are complex lesions that may require different microsurgical or endovascular strategies, and stent-assisted coiling (SAC) has emerged as a feasible alternative to treat this subset of aneurysms.

Methods: The objective was to assess the rate of complications of unruptured wide-necked IAs treated with SAC. We retrospectively identified patients with unruptured wide-necked IAs treated with SAC. Medical charts, procedure reports, and imaging studies were analyzed.

Results: One hundred twenty patients harboring 124 unruptured wide-necked IAs were included. Ninety-two aneurysms (74.2%) were located in the anterior circulation. The median aneurysm size was 7 mm (IQR = 5-10). The immediate complete aneurysm occlusion rate was 29% (36/124). The rate of procedural complications was 3.3 % (4/120), which included 2 intraprocedural aneurysm ruptures, 1 immediate postprocedure aneurysm rupture, and 1 vessel occlusion rescued with an open-cell stent. The median follow-up time was 21 months (IQR = 10.3-40.9). Kaplan-Meier analysis estimated a median time of complete aneurysm occlusion of 6.3 months (95%CI = 3.8-7.8). At 30-day follow-up, 80.7% of patients had a Glasgow Outcome Score (GOS) of 5 and at the latest follow-up 83.9%. Imaging follow-up was available for 102 patients. The rate of complete aneurysm occlusion was 73.5% (75/102), severe in-stent stenosis (>50%) was found in 1% (1/102), the recanalization rate was 6.6% (5/75), and the retreatment rate was 7.8% (8/102).

Conclusion: SAC remains a safe and effective technique to treat wide-necked IAs, providing a low rate of complications and recanalization with excellent long-term aneurysm occlusion rates.

Saccular or dissecting aneurysms involving the basilar trunk: Endovascular treatment and clinical outcome

Objectives: Basilar artery trunk aneurysms (BTAs) are a rare pathology and difficult to treat. We present our experience regarding angiographic results and clinical outcomes for 16 BTAs treated by reconstructive endovascular treatment (EVT) using stent or balloon. Methods: Between January 2003 and December 2014, 15 patients (mean age, 58.6 years; 11 males) with 16 BTAs were enrolled. Clinical manifestation, outcomes and procedural complications were evaluated retrospectively, and follow-up angiography was performed 12 and 24 months after procedure. Results: Subarachnoid hemorrhage (SAH) developed in seven aneurysms and nine were found incidentally. In one case, SAH followed by acute infarction on pons. The location of the aneurysms was the pure basilar artery (BA) trunk in 13 and the junction of the BA and the superior cerebellar artery in 3. Reconstructive EVT was technically successful in 15 aneurysms (93.8%) and failed in one due to the difficulty of vascular access. Stent/balloon-assisted coiling was performed in 13 aneurysms and sole stent therapy in two aneurysms. One patient had periprocedural complication of acute in-stent thrombosis. All treated patients had no symptoms with the usual activities except three patients, who died from myocardial infarction, aneurysmal rebleeding, and cerebellar infarction. Angiographic follow-up was performed in nine aneurysms; three aneurysms were recanalized (33.3%) and six aneurysms had no interval change (66.7%). There was no significant event during the follow-up period (mean, 23.5 months). Conclusion: In the treatment of BTAs, reconstructive EVT may provide a feasible and safe option to microsurgery.

Testing bioresorbable stent feasibility in a rat aneurysm model

Background

Advances in stent-assisted coiling have incrementally expanded endovascular treatment options for complex cerebral aneurysms. After successful coil consolidation and aneurysm occlusion, endovascular scaffolds are no longer needed. Thus, bioresorbable stents that disappear after aneurysm healing could avoid future risks of in-stent thrombosis and the need for lifelong antiplatelet therapy.

Objective

To assess the applicability and compatibility of a bioresorbable magnesium- alloy stent (brMAS) for assisted coiling.

Methods

Saccular sidewall aneurysms were created in 84 male Wistar rats and treated with brMAS alone, brMAS + aspirin, or brMAS + coils + aspirin. Control groups included no treatment (natural course), solely aspirin treatment, or conventional cobalt–chromium stent + coils + aspirin treatment. After 1 and 4 weeks, aneurysm specimens were harvested and macroscopically, histologically, and molecularly examined for healing, parent artery perfusion status, and inflammatory reactions. Stent degradation was monitored for up to 6 months with micro-computed and optical coherence tomography.

Results

Aneurysms treated with brMAS showed advanced healing, neointima formation, and subsequent stent degradation. Additional administration of aspirin sustained aneurysm healing while reducing stent-induced intraluminal and periadventitial inflammatory responses. No negative interaction was detected between platinum coils and brMAS. Progressive brMAS degradation was confirmed.

Conclusions

brMAS induced appropriate healing in this sidewall aneurysm model. The concept of using bioresorbable materials to promote complete aneurysm healing and subsequent stent degradation seems promising. These results should encourage further device refinements and clinical evaluation of this treatment strategy for cerebrovascular aneurysms.

Rosuvastatin- and Heparin-Loaded Poly(l-lactide- co-caprolactone) Nanofiber Aneurysm Stent Promotes Endothelialization via Vascular Endothelial Growth Factor Type A Modulation

This study explored a new rosuvastatin calcium- and heparin-loaded poly(l-lactide- co-caprolactone) (PLCL) scaffold for covered stents for treating aneurysms. The mechanism of rosuvastatin-induced endothelialization via vascular endothelial growth factor (VEGF)-A elevation was further explored. Rosu50, Rosu75, Rosu100, and phosphate-buffered saline (PBS) nanofibrous scaffolds were fabricated by coaxial electrospinning and observed by electron microscopy. Anticoagulation and pro-endothelialization properties were tested. Sixteen rabbits were selected for an in vivo assay and underwent microsurgery to establish a carotid aneurysm model. The animals were treated with covered stents and followed for 4 months using digital subtraction angiography (DSA), electron microscopy, and histology. Rosuvastatin-treated human umbilical vein endothelial cell (HUVEC) viability, function, and VEGF-A modulation were further studied to elucidate the pro-endothelialization mechanism of rosuvastatin. Our study demonstrates that rosuvastatin and heparin can be incorporated into PLCL nanofibers via electrospinning. Rosu100 nanofiber scaffolds exhibited significant anticoagulation properties. The viability of HUVECs transferred to Rosu100 nanofiber scaffolds was increased significantly. In vivo, DSA revealed that the Rosu100 group had better outcomes than the PBS group. In addition, the Rosu100 stents induced more integrated endothelialization. Further study demonstrated that rosuvastatin promoted HUVEC viability and function in vitro. The effects of rosuvastatin may be attributed to an elevation in VEGF-A. We demonstrated that rosuvastatin- and heparin-loaded PLCL-covered stents show favorable anticoagulation and pro-endothelialization properties in vitro and in vivo in a rabbit aneurysm model. VEGF-A elevation played a crucial role in rosuvastatin-promoted endothelialization. This work provides an additional option for treating cerebral aneurysms with covered stents.

Stents and Stent Mimickers in Endovascular Management of Wide-neck Intracranial Aneurysms

Subarachnoid hemorrhage due to a ruptured cerebral aneurysm is a disastrous event accounting for approximately 5%-15% of all stroke cases and has a high mortality rate. One of the major goals in the management of these patients is to prevent rebleeding by securing the aneurysm either surgically or by endovascular means. Endovascular treatment is considered the first line of treatment for intracranial aneurysms; however, wide-neck aneurysms (WNAs) are specifically difficult to treat by endovascular means due to the difficulty in achieving a stable coil mass inside the aneurysm sac. To overcome this problem, assisted endovascular treatment techniques and devices have evolved over the years. Amongst these, stent-assisted coiling (SAC) techniques provide a scaffold for coil embolization. The concept of the stent-assisted technique inspired creative pioneers to invent new tools like the PulseRider (Pulsar Vascular, Inc. CA, USA) and the pCONUS (Phenox GmbH, Germany), which are a great help in managing wide-neck and bifurcation aneurysms. The concept of stent within stents and its related hemodynamic effect has led to the novel development of flow diverters for reconstructing the arterial wall and correcting the hemodynamic disturbances. In this article, we review the stents and stent-like devices currently in practice for the endovascular management of wide-neck and branch intracranial aneurysms.

Update on flow diverters for the endovascular management of cerebral aneurysms

Flow diversion has become a well-accepted option for the treatment of cerebral aneurysms. Given the significant treatment effect of flow diverters, numerous options have emerged since the initial Pipeline embolization device studies. In this review, the authors describe the available flow diverters, both endoluminal and intrasaccular, addressing nuances of device design and function and presenting data on complications and outcomes, where available. They also discuss possible future directions of flow diversion.

Symptomatic delayed coil migration after balloon assisted embolization: An underreported adverse event?

Microsurgical clipping is still regarded as the gold-standard treatment for broad-neck intracranial aneurysms. New endovascular techniques like balloon or stent assisted coiling are quickly rising to the challenge and showing promising outcomes. As a result, broad-neck aneurysms are increasingly addressed by these techniques despite they have not been tested against clipping in a randomized controlled trial and long-term complications might be unknown yet. Intraprocedural coil migration has been well documented in the literature, but the same complication in a delayed fashion is scarcely reported. We present a case of delayed coil migration occurring after a balloon-assisted embolization of a wide-necked intracranial aneurysm and we perform a literature review for similar cases. We discuss how, despite seeming an extremely rare complication, with new endovascular techniques increasingly perceived as the safer option in any aneurysm, potential adverse events may become more frequent. Strategies proposed to address this developing scenario are also reviewed.

Utility of bulging technique for endovascular treatment of small and wide-necked aneurysms with a Low-profile Visualized Intraluminal Support (LVIS Jr.) device: A case report and review of the literature

Small and broad-necked aneurysms are generally very difficult to treat using endovascular therapy. The arrival of the low-profile stent (e.g., Low-profile Visualized Intraluminal Support; LVIS) has enabled reconstructive treatment for these aneurysms. In addition, the bulging technique using LVIS is an effective and attractive technique for performing stent-assisted coiling to preserve parent arteries and achieve neck coverage. We report here a patient with a small and wide-necked ruptured basilar artery (BA) top aneurysm, in whom successful treatment was achieved by stent-assisted coiling with LVIS Jr. using the bulging technique. A 74-year-old woman with moderate hypertension consulted for treatment of subarachnoid hemorrhage with a ruptured BA top aneurysm measuring 2.7 mm in height with a 4.3 mm neck. We initially tried emergency balloon-assisted coiling, but coiling proved difficult. We therefore performed stent-assisted coiling with LVIS Jr. using the bulging technique. The postoperative course was uneventful, with no aggravation of neurological symptoms, and the patient was discharged 14 days postoperatively. This treatment strategy with LVIS Jr. using the bulging technique may be very useful for patients with a ruptured aneurysm with a small and broad neck that would otherwise require treatment with intravascular devices or open surgery.

Stent-assisted coiling of cerebral aneurysms: a single-center clinical and angiographic analysis

Objective

This study retrospectively compared the clinical and angiographic outcomes of treating cerebral aneurysms with Neuroform (NEU), Enterprise (EP), and Low-profile Visualized Intraluminal Support (LVIS/LVIS Jr) stents.

Materials and methods

We conducted a retrospective analysis of a procedural database. All aneurysm procedures using any of the three types of self-expanding nitinol stents (NEU, EP and LVIS/LVIS Jr) were included. Intra-procedure complications, post-procedure complications, and angiographic results (Raymond–Roy grade scale, RRGS) were analyzed retrospectively. A multivariate logistic regression analysis was conducted to identify predictors of intra-procedure and post-procedure complications.

Results

Two hundred and forty-three aneurysms in 229 patients treated with stent-assisted coiling were included (NEU group: 109 aneurysms; EP group: 61 aneurysms; LVIS/LVIS Jr: 73 aneurysms). The LVIS/LVIS Jr group was associated with the lowest rate of initial complete occlusion (RRGS I: 47.9%; 35/73). Follow-up showed the proportion of RRGS I increased for all stent groups but was greatest in the LVIS/LVIS Jr group. Overall, 17 intra-procedural complications were seen in 229 patients (7.4%) and 15 post-procedural complications were found in 198 patients at follow-up (7.6%), with no differences between stent groups. Thrombotic events were the most common complications and occurred in 13 patients (13/229, 5.7%).

Conclusions

All three types of stents used to treat cerebral aneurysms with unfavorable neck were safe and effective, providing suitable support for the coil mass. LVIS/LVIS Jr promotes better progressive aneurysm complete occlusion than the other two stents but seems to cause more common intra-procedural stent-related thrombotic events and fewer post-procedural complications.

Endovascular management of fusiform aneurysms in the posterior circulation: the era of flow diversion

Fusiform aneurysms are uncommon compared with their saccular counterparts, yet they remain very challenging to treat and are associated with high rates of rebleeding and morbidity. Lack of a true aneurysm neck renders simple clip reconstruction or coil embolization usually impossible, and more advanced techniques are required, including bypass, stent-assisted coiling, and, more recently, flow diversion. In this article, the authors review posterior circulation fusiform aneurysms, including pathogenesis, natural history, and endovascular treatment, including the role of flow diversion. In addition, the authors propose an algorithm for treatment based on their practice.

Anchoring Pipeline Flow Diverter Construct in the Treatment of Traumatic Distal Cervical Carotid Artery Injury

Background

Traumatic extracranial internal carotid artery (ICA) dissections are uncommon and can be difficult to treat. Thinning of adventitia and dilatation may occur following arterial dissection, thus resulting in a fusiform pseudoaneurysm, which can subsequently cause bleeding, expanding, or pulsatile hematoma. Currently, medical management with anticoagulation remains the first line of treatment and yields good outcomes in 75% of cases with a mortality rate of 3-4%. Endovascular intervention is indicated with failure of medical therapy, progressive enlargement of a traumatic pseudoaneurysm, acute flow-related infarcts due to vessel occlusion, or when anticoagulation is contraindicated due to risk of pseudoaneurysm rupture and hemorrhage. Recognized interventional treatments include parent artery occlusion with or without revascularization, endovascular coil embolization, and covered stenting.

Summary

A wide variety of endovascular stents are available that are capable of opening a stenosed vessel while obliterating the associated false lumen and providing a scaffold for embolization of the pseudoaneurysm. The use of the Pipeline Embolization Device (PED) in the management of traumatic intracranial pseudoaneurysms has been described. However, there are few reports on the usage of the PED for treating traumatic extracranial ICA dissection and/or pseudoaneurysms. However, a potential complication of the use of PED in the extracranial ICA is a hypothetical tendency to migrate in a mobile vessel. Thus, the risk of migration of the PED has encouraged practitioners to adopt strategies to limit this risk.

Key Messages

We describe different techniques employed to anchor the flow-diverting construct within tortuous, mobile vessels.

Current Treatment Strategies for Intracranial Aneurysms: An Overview

Intracranial aneurysm is a leading cause of stroke. Its treatment has evolved over the past 2 decades. This review summarizes the treatment strategies for intracranial aneurysms from 3 different perspectives: open surgery approach, transluminal treatment approach, and new technologies being used or trialed. We introduce most of the available treatment techniques in detail, including contralateral clipping, wrapping and clipping, double catheters assisting coiling and waffle-cone technique, and so on. Data from major trials such as Analysis of Treatment by Endovascular approach of Non-ruptured Aneurysms (ATENA), Internal Subarachnoid Trial (ISAT), Clinical and Anatomical Results in the Treatment of Ruptured Intracranial Aneurysms (CLARITY), and Barrow Ruptured Aneurysm Trial (BRAT) as well as information from other clinical reports and local experience are reviewed to suggest a clinical pathway for treating different types of intracranial aneurysms. It will be a valuable supplement to the current existing guidelines. We hope it could help assisting real-time decision-making in clinical practices and also encourage advancements in managing the disease.

Low-profile Visualized Intraluminal Support Junior Device for the Treatment of Intracranial Aneurysms

Objective: Early case series suggest that the recently introduced Low-profile Visualized Intraluminal Support Junior (LVIS Jr.) device (MicroVention-Terumo, Inc., Tustin, CA) may be used to treat wide-necked aneurysms that would otherwise require treatment with intrasaccular devices or open surgery. We report our single-center experience utilizing LVIS Jr. to treat intracranial aneurysms involving 1.8-2.5 mm parent arteries.

Methods: We retrospectively reviewed records of patients treated with the LVIS Jr. device for intracranial aneurysms at a single center. A total of 21 aneurysms were treated in 18 patients. Aneurysms were 2-25 mm in diameter; one was ruptured, while three had recurred after previous rupture and treatment. Lesions were distributed across the anterior (n=12) and posterior (n=9) circulations. Three were fusiform morphology.

Results: Stent deployment was successful in 100% of cases with no immediate complications. Seventeen aneurysms were treated with stent-assisted coil embolization resulting in immediate complete occlusion in 94% of cases. Two fusiform aneurysms arising from the posterior circulation were further treated with elective clip ligation after delayed expansion and recurrence; no lesions required further endovascular treatment. Four aneurysms were treated by flow diversion with stand-alone LVIS Jr. stent, and complete occlusion was achieved in three cases. Small foci of delayed ischemic injury were noted in two patients in the setting of antiplatelet medication noncompliance. No in-stent stenosis, migration, hemorrhage, or permanent deficits were observed. Good functional outcome based on the modified Rankin Scale score (mRS ≤ 2) was achieved in 100% of cases.

Conclusion: Our midterm results suggest that the LVIS Jr. stent may be used for a variety of intracranial aneurysms involving small parent arteries (1.8-2.5 mm) with complete angiographic occlusion, parent vessel preservation, and functional clinical outcomes. This off-label expansion would increase the number of aneurysms amenable to endovascular treatment. Future studies may build upon our experiences with flow diversion and treatment of complex or multiple lesions.

Manufacture of patient-specific vascular replicas for endovascular simulation using fast, low-cost method

Patient-specific vascular replicas are essential to the simulation of endovascular treatment or for vascular research. The inside of silicone replica is required to be smooth for manipulating interventional devices without resistance. In this report, we demonstrate the fabrication of patient-specific silicone vessels with a low-cost desktop 3D printer. We show that the surface of an acrylonitrile butadiene styrene (ABS) model printed by the 3D printer can be smoothed by a single dipping in ABS solvent in a time-dependent manner, where a short dip has less effect on the shape of the model. The vascular mold is coated with transparent silicone and then the ABS mold is dissolved after the silicone is cured. Interventional devices can pass through the inside of the smoothed silicone vessel with lower pushing force compared to the vessel without smoothing. The material cost and time required to fabricate the silicone vessel is about USD $2 and 24 h, which is much lower than the current fabrication methods. This fast and low-cost method offers the possibility of testing strategies before attempting particularly difficult cases, while improving the training of endovascular therapy, enabling the trialing of new devices, and broadening the scope of vascular research.

Acute Pontine Infarction due to Basilar Artery Dissection from Strenuous Physical Effort: One from Sexual Intercourse and Another from Defecation

A basilar artery dissection (BAD) is an extremely rare disease. It can lead to hemorrhage or infarction involving the brain stem, and is often associated with grave outcome. However, little is known about the pathophysiology of BAD, and its proper managements are yet in controversy. Herein, we report on two rare cases of basilar artery dissection from strenuous physical effort; one from sexual intercourse and another from defecation. The treatment modalities and the outcomes are also discussed.

Treatment of wide-necked aneurysms with the Low-profile Visualized Intraluminal Support (LVIS Jr) device: a multicenter experience

BACKGROUND

The Low-profile Visualized Intraluminal Support (LVIS) Junior stent is newly approved for the treatment of wide-necked intracranial aneurysms.

OBJECTIVE

To report our multicenter experience with use of the LVIS Jr device.

METHODS

The neurointerventional databases of the participating institutions were retrospectively reviewed for aneurysms treated with LVIS Jr from the time of Food and Drug Administration approval until February 2016. All patients in the study period were included. Clinical presentation, aneurysm location, aneurysm size, vessel size, procedural complications, clinical and imaging follow-up were included in the analysis.

RESULTS

Eighty-five patients (54 female and 31 male) met the inclusion criteria for the study. Sixty-eight (80%) of the aneurysms were unruptured and the remainder were ruptured. The most common location of the treated aneurysms was anterior communicating artery (36%), middle cerebral artery bifurcation (22%), and basilar terminus (15%). The mean aneurysm size was 6.1 mm. The mean minimum parent vessel size was 2.3 mm. The LVIS Jr was successfully deployed in all but one case (99%). Initial angiographic results demonstrated Roy-Raymond class 1-2 occlusions in 61/84 patients (73%). At 6 months, 85% of the patients seen at follow-up had Roy-Raymond class 1-2 aneurysm occlusion. No procedure-related deaths occurred. Two cases of procedure-related complications (intraprocedural rupture and delayed rupture at day 2) were seen, leading to permanent neurologic morbidity. Both these cases were in patients with ruptured aneurysms.

CONCLUSIONS

The LVIS Jr is a technically feasible, safe, and effective treatment for wide-necked intracranial aneurysms. Early results are promising but will need to be corroborated with longer-term follow-up.

Intracranial Stenting for Cerebrovascular Pathology

After reading this article, the participant should be able to:

Describe the use of stent-assisted angioplasty for intracranial atherosclerotic disease. Recall the present status of stent-assisted managment of intracranial aneurysms. Describe the role of stenting and its technical aspects in the treatment of arteriovenous fistulae and acute stroke.

Stent-Assisted Angioplasty of Intracranial Vertebrobasilar Atherosclerosis: The Best Therapeutic Option in Recurrent Transient Ischemic Events Unresponsive to Anticoagulant Treatments

Atherosclerotic stenosis of the posterior circulation refractory to medical treatment generally has a poor prognosis resulting in a high morbidity-mortality rate and the recurrence of ischemic events. Extracranial bypass in the vertebrobasilar system is possible but is also associated with high morbidity (3–21%) and mortality (13–55%)1,2, and has not been demonstrated to reduce the risk of stroke. Percutaneous angioplasty alone has also not shown favorable results, and further, has been associated with a remarkable number of complications. The improvement resulting from endovascular therapy has taken the treatment of this pathology to a new dimension. We describe eight patients with severe symptomatic basilar artery stenosis who, in addition to medical therapy, were treated by our service with angioplasty and stent placement. Three of them received urgent treatment. All patients suffering from severe stenosis of the basilar artery were treated by the insertion of balloon expandable stents. The degree of pre-stent stenosis was approximately 80% in all cases, and was reduced to 5–10% after the stent implant. There were no complications during treatment. There has not been a recurrence of symptoms or a new ischemic lesion during the one-year follow-up period. Endovascular therapy with a balloon expandable stent or angioplasty plus stent are presented as improved choices for treatment of patients with severe basilar artery stenosis refractory to medical treatment.