Guglielmi detachable coil embolization of cerebral aneurysms: 11 years' experience

Vascular embolic nanobiomaterials for efficient tumor treatment

Embolization is a minimally invasive cancer treatment method. Embolization involves artificially blocking blood flow using an embolic agent to block abnormal blood vessels that supply nutrients or oxygen to a specific lesion, thereby killing the lesion, inhibiting its growth, and stopping bleeding. Currently, polyvinyl alcohol (PVA) and gelatin are the most popular embolic agents. These substances are available in various sizes and shapes that physically obstruct blood flow to cause vascular embolization. They are commonly used due to their ease of use and low cost. However, they can cause side-effect such as bleeding and potential complications related to catheter- and insertion-related complications. Recently, nanobiomaterials have been explored as embolization agents with high biocompatibility, such as liquid metals, and can be used with autologous blood. In this review, we cover the types of embolic agents currently used in cancer treatment and focus on those with fewer adverse effects and minimal vascular damage, followed by discussions on new embolic agents under development. Additionally, we explore potential future research directions for developing better embolic agents.

CFD investigations of a shape-memory polymer foam-based endovascular embolization device for the treatment of intracranial aneurysms

The hemodynamic and convective heat transfer effects of a patient-specific endovascular therapeutic agent based on shape-memory polymer foam (SMPf) are evaluated using computational fluid dynamics studies for six patient-specific aneurysm geometries. The SMPf device is modeled as a continuous porous medium with full expansion for the flow studies and with various degrees of expansion for the heat transfer studies. The flow simulation parameters were qualitatively validated based on the existing literature. Further, a mesh independence study was conducted to verify an optimal cell size and reduce the computational costs. For convective heat transfer, a worst-case scenario is evaluated where the minimum volumetric flow rate is applied alongside the zero-flux boundary conditions. In the flow simulations, we found a reduction of the average intra-aneurysmal flow of > 85% and a reduction of the maximum intra-aneurysmal flow of > 45% for all presented geometries. These findings were compared with the literature on numerical simulations of hemodynamic and heat transfer of SMPf devices. The results obtained from this study provide a novel and practical framework for optimizing the design of patient-specific SMPf devices, integrating advanced computational models of hemodynamics and heat transfer. This framework could guide the future development of personalized endovascular embolization solutions for intracranial aneurysms with improved therapeutic outcome.

Safety and efficacy of staged primary coiling followed by delayed flow diversion of ruptured intracranial aneurysms: A systematic review and meta-analysis

BACKGROUND

Ruptured intracranial aneurysms lead to significant mortality and morbidity. Recent advancements have suggested staged coiling with subsequent flow diverter stent placement may reduce the risk of hemorrhage with dual antiplatelet therapy (DAPT) or stent thrombosis in the acute inflammatory phase after aneurysm rupture while still appropriately mitigating risk of aneurysmal rehemorrhage.

MATERIALS AND METHODS

A systematic review and single-arm meta-analysis was conducted. Studies reporting patients receiving coiling followed by delayed flow diverter placement on a separate day were included.

RESULTS

Five studies, comprising 94 patients, were included for meta-analysis. Average time between procedures ranged from 9.8 to 169 days; 24% (95% CI: 10-41%) of patients had a poor functional neurologic outcome (modified Rankin Scale > 2) at discharge compared to 4% (0-11%) at last follow-up. There was one incidence of rehemorrhage between treatments, 0% (0-4%). Vasospasm after coiling was the most common adverse event, 16% (1-41%). There was low risk of ischemic complications [1% (0-8%) with coil placement and 5% (1-11%) with stent placement]. Intraprocedural intracranial hemorrhage was also rare (two patients during coil placement; no cases during stent placement). There were no significant differences if flow diversion was performed less than or greater than 100 days from coiling.

CONCLUSIONS

Our study highlights the benefit of primary coiling with staged flow diversion for the management of ruptured intracranial aneurysms with a low risk for complications. Namely, the rate of rebleeding between treatments was exceptionally low. We advocate for the greater consideration of this treatment combination in the treatment of ruptured intracranial aneurysms.

Hemodynamic Evaluation of Residual Cavity Growth in a Basilar-Tip Cerebral Aneurysm Post-coiling Using Silent Magnetic Resonance Angiography (MRA): A Case Report

Coil embolization of cerebral aneurysms often encounters challenges in achieving complete filling of the aneurysm sac due to complex shapes and hemodynamic factors, frequently resulting in the formation of a residual cavity (RC) at the aneurysm neck. The hemodynamic mechanisms underlying RC formation and growth, however, remain poorly understood. Computational fluid dynamics (CFD) analysis, combined with silent MRA free from contrast agents and metal artifacts, offers a promising approach to elucidate these mechanisms, potentially enhancing the clinical management of cerebral aneurysms post-coiling. Herein, we report a case of a basilar-tip aneurysm treated with coil embolization, where sequential silent MRA and CFD analysis were employed to investigate hemodynamic factors driving rapid RC growth. Initial RC formation was attributed to coil compaction driven by flow impingement at the aneurysm neck onto the neo-endothelial surface, contributing to vertical growth. In contrast, secondary flows detached from the main inflow jet were observed in distal regions of the RC, leading to flow stagnation, wall vulnerability, and subsequent horizontal expansion of the aneurysmal wall. This case highlights the role of secondary detached flows in RC enlargement, emphasizing their potential to weaken the aneurysm wall and drive sac expansion. CFD analysis using silent MRA is a valuable tool for understanding RC hemodynamics and post-coiling management for cerebral aneurysms.

The Woven EndoBridge device as a good alternative treatment for stent assisted coiling in intracranial bifurcation aneurysms: a systematic review and meta-analysis

OBJECTIVES

The Woven EndoBridge (WEB), functioning as an intrasaccular disruption device, offers a novel option for complex aneurysms, particularly bifurcation aneurysms. In this systematic review and meta-analysis, our goal is to compare the safety and efficacy of WEB devices with stent-assisted coiling (SAC) for intracranial bifurcation aneurysms.

METHODS

We conducted a systematic search of PubMed, Scopus, and Embase, and Web of Science databases in September 2024 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We aimed to compare aneurysmal occlusion, procedural time, the retreatment, and complication rates as secondary objectives. The comparison between the two techniques was performed using a weighted random-effects model, and the quality of the studies was assessed using the Newcastle-Ottawa Scale (NOS) for cohort studies.

RESULTS

The authors analyzed five studies encompassing 298 and 203 patients in SAC and WEB groups, respectively. Complete (OR, 0.97; 95%CI: 0.63-1.49, I2 = 0%) and adequate (OR: 0.88; 95%CI: 0.51-1.5, I2 = 0%) occlusion didn't differ between two groups. The overall procedural time mean difference was 38.2 min, significantly higher in the SAC group (95%CI, 26.9-49.6, I2 = 53.4%). Retreatment rates did not significantly differ between the two groups (OR: 1.34; 95%CI: 0.37-4.85, I2 = 61.7%). The SAC group experienced more complications during and after the operation (OR, 2.82; 95%CI: 1.07-7.44, I2 = 0%). The pooled follow-up duration was 22.1 and 13.5 months for SAC and WEB groups respectively.

CONCLUSION

The WEB demonstrates comparable efficacy in occluding bifurcation aneurysms compared to SAC, with the added benefits of reduced procedural time and lower complication rates.

CFD investigations of a shape-memory polymer foam-based endovascular embolization device for the treatment of intracranial aneurysms

The hemodynamic and convective heat transfer effects of a patient-specific endovascular therapeutic agent based on shape memory polymer foam (SMPf) are evaluated using computational fluid dynamics studies for six patient-specific aneurysm geometries. The SMPf device is modeled as a continuous porous medium with full expansion for the flow studies and with various degrees of expansion for the heat transfer studies. The flow simulation parameters were qualitatively validated based on the existing literature. Further, a mesh independence study was conducted to verify an optimal cell size and reduce the computational costs. For convective heat transfer, a worst-case scenario is evaluated where the minimum volumetric flow rate is applied alongside the zero-flux boundary conditions. In the flow simulations, we found a reduction of the average intra-aneurysmal flow of > 85% and a reduction of the maximum intra-aneurysmal flow of > 45% for all presented geometries. These findings were compared with the literature on numerical simulations of hemodynamic and heat transfer of SMPf devices. The results obtained from this study can serve as a guide for optimizing the design and development of patient-specific SMPf devices aimed at personalized endovascular embolization of intracranial aneurysms.

Intermediate catheter use is associated with intraprocedural rupture during coil embolization of ruptured intracranial aneurysms: a retrospective propensity score-matched study

Introduction

An intermediate catheter (IMC) may pose a risk of intraprocedural rupture (IPR) during coil embolization of ruptured intracranial aneurysms (RIAs), because the pressure on the microcatheter and coil might be more direct. To verify this hypothesis, this study explored whether use of an IMC might correlate with an increased rate of IPR during coil embolization for RIAs.

Methods

We retrospectively reviewed 195 consecutive aneurysms in 192 patients who underwent initial coil embolization for saccular RIAs at our institution between January 2007 and December 2023. Patients were divided into two groups with aneurysms treated either with an IMC (IMC group) or without an IMC (non-IMC group). To investigate whether IMC use increased the rate of IPR, a propensity score-matched analysis was employed to control for age, sex, maximal aneurysm size, neck size, bleb formation, aneurysm location, proximal vessel tortuosity, balloon-assisted coiling, type of microcatheter, and type of framing coil.

Results

Ultimately, 43 (22%) coil embolization used IMC. In univariate analysis, the incidence of IPR was significantly higher in the IMC group compared with the non-IMC group (14.0 vs. 3.3%, p = 0.016). Propensity score matching was successful for pairs of 26 aneurysms in the IMC group and 52 aneurysms in the non-IMC group. The incidence of IPR was still significantly higher in the IMC group than in the non-IMC group (23.1 vs. 3.8%, p = 0.015). No significant differences in the incidences of ischemic complications and IMC-related parent artery dissection were observed between the two groups.

Discussion

When using IMC for coil embolization of RIAs, the surgeons should be more careful and delicate in manipulating the microcatheter and inserting the coils to avoid IPR.

Antiplatelet Therapy in Endovascular Treatment of Cerebral Aneurysms

Thromboembolism is one of the main causes of severe complications in the endovascular treatment of cerebral aneurysms, and antiplatelet therapy (APT) is necessary to prevent such complications. Conversely, prolonged APT has the potential risk of hemorrhagic complications; therefore, the timing of dose reduction or discontinuation is an important aspect of periprocedural APT. However, no clinical evidence of an optimal regimen of APT for cerebral aneurysms exists, and the selection, dosage, duration, or combination of antiplatelets has been dependent on physicians for unruptured or ruptured cerebral aneurysms. Many reports have shown that preoperative APT can reduce ischemic complications without increasing hemorrhagic complications, and some reports have shown that the P2Y12 reaction unit (PRU) value measured using the VerifyNow (Werfen, Barcelona, Spain) system is associated with periprocedural ischemic and hemorrhagic complications. Appropriate dose and duration management adjustments based on the platelet reactivity test, aneurysm morphology, treatment, and patient background may contribute to good outcomes. Although accumulating evidence exists regarding the efficacy of preoperative APT, there is no evidence regarding the optimal duration or discontinuation of APT.

Mid-term safety and efficacy in small intracranial aneurysm coiling: results from TARGET® nano prospective independent core lab adjudicated multicenter registry

Background

The primary objective is to evaluate the safety and effectiveness of Stryker second generation Target® Nano Coils in the treatment of ruptured and unruptured small (<7 mm) intracranial aneurysms.

Methods

The TARGET Registry is a prospective, two-arm study with independent medical event monitoring and core-lab adjudication. This paper describes the second arm of the TARGET registry. Patients with de novo intracranial aneurysms were embolized with 2nd generation TARGET Nano coils in 12 US centers. The primary efficacy outcome was adequate aneurysm occlusion (RR occlusion grade I-II) on follow-up. Primary safety outcome was treatment-related morbidity and mortality. Secondary outcomes included aneurysm packing density immediately post-procedure, immediate adequate occlusion, aneurysm re-access rate, retreatment rate and clinical outcomes using modified ranking scale. A secondary analysis investigated the influence of using Nano-predominant coils (≥2/3 of total coil-length) vs. non-Nano-predominant coils (<2/3 of total length).

Results

150 patients with 155 aneurysms met the inclusion and exclusion criteria. (31%) patients with ruptured and (69%) with unruptured aneurysms were treated using TARGET coils. Median age was 58.8 (SD 12.7), 74.7% were females, and 80% were Caucasians. Mean follow-up was 5.23 (SD 2.27) months. Peri-procedural mortality was seen in 2.0% of patients. Good outcome at discharge (mRS 0-2) was seen in 81.3% of the cohort. The median packing density (SD) was 29.4% (14.9). Mid-term complete/near complete occlusion rate was seen in 96% of aneurysms and complete obliteration was seen in 75.2% of aneurysms. Patients treated predominantly with Nano coils had higher PD (32.6% vs. 26.1%, p < 0.001). There was no significant difference in clinical and angiographic outcomes. The mid-term mRS0-2 was achieved in 106/109 (97.2%) patients. All-cause mortality was 5/115 (4.3%).

Conclusion

In the multicenter TARGET Registry, 75.8% of aneurysms achieved mid-term complete occlusion, and 96% achieved complete/near complete occlusion with excellent independent functional outcome.

Treatment of giant intracranial aneurysms using the Pipeline flow-diverting stent: Long-term results from the International Retrospective Study of the Pipeline Embolization Device (IntrePED) study

BACKGROUND

Traditional endovascular treatments of giant intracranial aneurysms are associated with high rates of complications and retreatment. Our objective was to examine the safety and long-term efficacy of the Pipeline Embolization Device for treatment of these aneurysms.

METHODS

This retrospective study using the IntrePED database included all patients with giant intracranial aneurysms treated with the Pipeline device between July 2008 and February 2013. Efficacy outcomes were stratified by using the Raymond-Roy Occlusion Classification. Predefined safety outcomes included spontaneous rupture of the target aneurysm; ipsilateral intracranial hemorrhage; ischemic stroke; parent artery stenosis; and sustained cranial neuropathy.

RESULTS

Sixty-six embolizations were performed to treat 63 giant intracranial aneurysms (including 2 ruptured): 49 (77.8%) in the anterior and 14 (22.2%) in the posterior circulation. The median follow-up was 22.4 (0.1-60.5) months. Class I angiographic occlusion was achieved in 72.0% (36/50). The neurological morbidity/mortality rate was 23.8% (15/63), with higher rates in the posterior circulation than in the anterior circulation (22.4% vs. 28.6%). Among seven deaths, five had neurological causes. The procedure-related neurological morbidity and mortality rates were 22.7% (15/66) and 7.6% (5/66), respectively. The spontaneous rupture rate was 4.5% (3/66). Two spontaneous ruptures (1 death), 4/4 postprocedural intracranial hemorrhages, and 6/9 ischemic events occurred within 30 days. In-stent stenosis and new-onset cranial neuropathy were not observed during the angiographic follow-up period.

CONCLUSIONS

Although procedure-related neurological morbidity/mortality rates were not insignificant, this study confirms the feasibility and long-term efficacy of the Pipeline Embolization Device to treat giant intracranial aneurysms.

Systematic Review and Meta-Analysis of Endovascular Therapy Effectiveness for Unruptured Saccular Intracranial Aneurysms

Background

Currently, endovascular treatment of intracranial aneurysms (ICAs) is limited by low complete occlusion rates. The advent of novel endovascular technology has expanded the applicability of endovascular therapy; however, the superiority of novel embolic devices over the traditional Guglielmi detachable coils (GDCs) is still debated. We performed a systematic review of literature that reported Raymond-Roy occlusion classification (RROC) rates of modern endovascular devices to determine their immediate and follow-up occlusion effectiveness for the treatment of unruptured saccular ICAs.

Methods

A search was conducted using electronic databases (PUBMED, Cochrane, ClinicalTrials.gov, Web of Science). We retrieved studies published between 2000-2022 reporting immediate and follow-up RROC rates of subjects treated with different endovascular ICA therapies. We extracted demographic information of the treated patients and their reported angiographic RROC rates.

Results

A total of 80 studies from 15 countries were included for data extraction. RROC rates determined from angiogram were obtained for 21,331 patients (72.5% females, pooled mean age: 58.2 (95% CI: 56.8-59.6), harboring 22,791 aneurysms. The most frequent aneurysm locations were the internal carotid artery (46.4%, 95% CI: 41.9%-50.9%), the anterior communicating artery (26.4%, 95% CI: 22.5%-30.8%), the middle cerebral artery (24.5%, 95% CI:19.2%-30.8%) and the basilar tip (14.4%, 95% CI:11.3%-18.3%). The complete occlusion probability (RROC-I) was analyzed for GDCs, the Woven EndoBridge (WEB), and flow diverters. The RROC-I rate was the highest in balloon-assisted coiling (73.9%, 95% CI: 65.0%-81.2%) and the lowest in the WEB (27.8%, 95% CI:13.2%-49.2%). The follow-up RROC-I probability was homogenous in all analyzed devices.

Conclusions

We observed that the coil-based endovascular therapy provides acceptable rates of complete occlusion, and these rates are improved in balloon-assisted coils. Out of the analyzed devices, the WEB exhibited the shortest time to achieve >90% probability of follow-up complete occlusion (~18 months). Overall, the GDCs remain the gold standard for endovascular treatment of unruptured saccular aneurysms.

A predictive model for the recurrence of intracranial aneurysms following coil embolization

Objective

This study aimed to identify risk factors for intracranial aneurysms (IAs) recurrence and establish a predictive model to aid evaluation.

Methods

A total of 302 patients with 312 IAs undergoing coil embolization between September 2017 and October 2022 were divided into two groups based on digital subtraction angiography follow-up. Clinical characteristics, operation-related factors, and morphologies were measured. Cox proportional hazard regression was used to identify the risk factors. Hazard ratios (HRs) were used to score points, and a predictive model was established. The test cohorts consisted of 51 IAs. Receiver operating characteristic curves were generated to determine the cutoff values and area under the curves (AUCs). A Delong test was performed to compare the AUCs.

Results

Diameter maximum (D max) (p < 0.001, HR = 1.221), Raymond-Roy occlusion classification (RROC) II or III (p = 0.004, HR = 2.852), and ruptured status (p < 0.001, HR = 7.782) were independent risk factors for the recurrence of IAs. A predictive model was established: D max + 2 * RROC (II or III; yes = 1, no = 0) + 6 * ruptured status (yes = 1; no = 0). The AUC of the predictive model (0.818) was significantly higher than those of D max (0.704), RROC (II or III) (0.645), and rupture status (0.683), respectively (Delong test, p < 0.05). The cutoff values of the predictive model and D max were 9.75 points and 6.65 mm, respectively.

Conclusion

The D max, RROC (II or III), and ruptured status could independently predict the recurrence of IAs after coil embolization. Our model could aid in practical evaluations.

Coils embolization use for coronary procedures: Basics, indications, and techniques

The use of coils is fundamental in interventional cardiology and can be lifesaving in selected settings. Coils are classified by their materials into bare metal, fiber coated, and hydrogel coated, or by the deliverability method into, pushable or detachable coils. Coils are delivered through microcatheters and the choice of coil size is important to ensure compatibility with the inner diameter of the delivery catheter, firstly to be able to deliver and secondly to prevent the coil from being stuck and damaged. Clinically, coils are used in either acute or in elective setting. The most important acute indication is typically the sealing coronary perforation. In the elective settings, coils can be used for the treatment of certain congenital cardiac abnormalities, aneurysms, fistulas or in the treatment of arterial side branch steal syndrome after CABG. Coils must always be delivered under fluoroscopy guidance. There are some associated complications with coils that can be acute or chronic, that nictitates regular followed-up. There is a need for education, training and regular workshops with hands-on to build the experience to use coils in situations that are infrequently encountered.

Risk factors for perianeurysmal vasogenic oedema (pavo) following embolization therapy: literature review

Perianeurysmal vasogenic oedema (PAVO) is a rare complication associated post-embolisation of intracranial aneurysms. The prevalence, risk factors predisposing to susceptibility, and pathologic mechanisms underlying this process are not clearly understood. Since this complication may be associated with poor clinical outcomes, the authors designed this study to describe possible risk factors, underlying mechanisms, and management of PAVO through published case reports. Developing a priori protocol according to PRISMA guidelines, we searched MEDLINE/PubMed, Embase and Web of Science to identify case studies and reports of adult patients with intracranial aneurysms who developed perianeurysmal oedema following coil embolization therapy. Data extracted from these studies included patient demographics, aneurysm characteristics, coil type, PAVO characteristics, treatment, and outcomes. Quality was assessed using a standardized tool. 21 eligible studies of acceptable quality were identified, comprising 40 unique cases from 9 countries. The mean patient age was 56.4 years and 25 (62.5%) were female. Aneurysm size ranged from 6 to 30 mm, with a mean size of 15.2 mm; only 6 (15%) of cases were giant intracranial aneurysm (≥ 25 mm). The more frequent locations of intracranial aneurysms associated with PAVO were the ICA (50%) and posterior circulation (32.5%), with 7.5% and 10% of cases occurring in MCA and anterior circulation, respectively. 16 cases (40%) were treated with bare platinum coils, and 14 (35%) with a combination of BPCs and bioactive coils; in 10 cases (25%), the coil type was not mentioned. PAVO presented between 0 days and 8 years of coil embolization, with 23 (57.5% cases) presenting symptomatically in relation to brain region affected. Management strategies for PAVO included conservative, steroids, re-embolization, clipping, stenting, parent artery occlusion either as monotherapy or as combination therapy. Of reported studies, 26 treated cases (65%) resolved, with 8 (20%) remaining stable, and 4 (10%) deteriorating. PAVO can be associated with small or large intracranial aneurysms, bare and bioactive platinum coils, and all regions of the intracranial circulation. The understanding of the risk factors of this complication lies in the underlying mechanisms, which will ultimately guide appropriate patient follow-up and subsequent optimal management.

Large, Wide-Neck, Side-Wall Aneurysm Treatment in Canines Using NeuroCURE: A Novel Liquid Embolic

BACKGROUND

Untreated intracranial aneurysms can rupture and result in high rates of morbidity and mortality. Although there are numerous approved endovascular aneurysm treatment devices, most require dual anti-platelet therapy, are minimally biocompatible, or are prone to recanalization. Neurovascular Controlled Uniform Rapid Embolic (NeuroCURE) is an innovative polymer gel material with long-term stability, biocompatibility, and hemocompatibility developed for the treatment of large, wide-neck aneurysms.

METHODS

Sidewall aneurysms were surgically created in 10 canines and NeuroCURE was injected through a 0.025 microcatheter under a single balloon inflation period. Aneurysm treatment was angiographically assessed post-embolization and pre-term with Raymond-Roy occlusion classification and a qualitative flow grade scale. Aneurysm neck stability and biocompatibility was histologically assessed to grade platelet/fibrin thrombus, percent endothelialization, and neointimal formation. Aneurysm sac stability was assessed by NeuroCURE sac content, inflammation, and neo-angiogenesis scales.

RESULTS

Explanted aneurysms exhibited a smooth surface at the aneurysm neck with nearly complete neointimal coverage at 3-months. By 6-months, neck endothelialization was 100% in all animals (average Raymond-Roy occlusion classification of 1.2), with no instances of aneurysm recanalization or parent vessel flow compromise. Biocompatibility assessments verified a lack of inflammatory response, neo-angiogenesis, and platelet/fibrin thrombus formation.

CONCLUSION

The NeuroCURE material promotes progressive occlusion of wide-necked side wall aneurysms over time without the need for dual antiplatelet agents. NeuroCURE also promotes neointimal tissue infill without dependence on thrombus formation and thus resists aneurysm recanalization. NeuroCURE remains a compelling investigational device for the treatment of intracranial aneurysms.

Variability of response on prophylactic prasugrel for endovascular treatment of intracranial aneurysms: Clinical implications

BACKGROUND AND PURPOSE

Prophylactic prasugrel for endovascular treatment of intracranial aneurysms has been introduced and increased, but HTPR (high on-treatment platelet reactivity) or LTPR (low on-treatment platelet reactivity) of prasugrel is not uncommon in clinical circumstances. To investigate the predisposing factors of HTPR and LTPR on prasugrel premedication in the neurointerventional field and to determine its clinical implications.

MATERIALS AND METHODS

Between February 2016 and December 2020, 191 patients treated with coil embolization using prophylactic prasugrel in 234 intracranial aneurysms were the final candidates for this study. Patient and aneurysm characteristics, clinical status, and laboratory study values were carefully reviewed retrospectively. We performed risk factor analyses for HTPR and LTPR on prasugrel.

RESULTS

Ultimately, 20 patients (10.5%) had HTPR, and 74 patients (38.7%) were categorized as having LTPR. In multivariable analyses, the factors related to HTPR were BMI (adjusted OR 1.21, 95% CI 1.04-1.41, p = 0.01), history of antithrombotics (adjusted OR 3.79, 95% CI 1.39-10.34, p = 0.01), and hematocrit (adjusted OR 0.91, 95% CI 0.84-0.99, p = 0.03). Low BMI was the only risk factor for LTPR (adjusted OR 0.84, 95% CI 0.76-0.94, p = 0.001).

CONCLUSION

In the neurointerventional field, high BMI and prior use of antithrombotic agents were related to HTPR, and low BMI was associated with LTPR on prophylactic prasugrel. High hematocrit levels decreased the risk of HTPR. When preparing endovascular treatment for intracranial aneurysms, attention to patients with these clinical features is required to address the possibility of ischemic or bleeding complications.

Robotically-assisted neuro-endovascular procedures: Single-Center Experience and a Review of the Literature

INTRODUCTION

Robotics could expand treatment of rapidly progressive pathologies such as acute ischemic stroke, with the potential to provide populations in need prompt access to neuro-endovascular procedures.

METHODS

Robotically-assisted (RA) neuro-endovascular procedures (RANPs) performed at our institution were retrospectively examined (RA-group, RG). A control group of manual neuro-endovascular procedures was selected (manual group, MG). Total operating room (OR) time, procedural time, contrast media use, fluoroscopy time, conversion from RA to manual control, procedural success, and complication rates were compared. A learning curve was identified.

RESULTS

Forty-one (41) RANPs were analyzed. Ages ranged from 20-82 y.o. Indications included diagnostic cerebral angiography (37), extracranial carotid artery stenting (3), and transverse sinus stent (1). Total OR time was longer in RG (median 86 vs. 71 min, p < 0.01). Procedural time (median 56 vs. 45 min, p = 0.12), fluoroscopy time (median 12 vs. 12 min, p = 0.69) and contrast media usage (82 vs. 92 ml, p = 0.54) were not significantly different. Patient radiation exposure was similar, considering similar fluoroscopy times. Radiation exposure and lead apron use were virtually absent for the main surgeon in RG. Procedural success was 83% and conversion from RA to manual control was 17% in RG. No treatment-related complications occurred. A learning curve showed that, after the fifth procedure, procedural times reduced and stabilized.

CONCLUSIONS

This series may contribute to further demonstrating the safety and feasibility of RANPs. RANPs can potentially reduce radiation exposure and physical burden for health personnel, expand acute cerebrovascular treatment to underserved areas, and enhance telementoring. Prospective studies are necessary for results to be generalized.

The Influence of Aneurysm Size on the Outcomes of Endovascular Management for Aneurysmal Subarachnoid Hemorrhages: A Comparison of the Treatment Results of Patients with Large and Small Aneurysms

The influence of aneurysm size on the outcomes of endovascular management (EM) for aneurysmal subarachnoid hemorrhages (aSAH) is poorly understood. To evaluate the outcomes of EM for ruptured large cerebral aneurysms, we retrospectively analyzed the medical records of patients with aSAH that were treated with coiling between 2013 and 2020 and compared the differences in outcomes depending on aneurysm size. A total of 469 patients with aSAH were included; 73 patients had aneurysms measuring ≥10 mm in diameter (group L), and 396 had aneurysms measuring <10 mm in diameter (group S). The median age; the percentage of patients that were classified as World Federation of Neurological Surgeons grade 1, 2, or 3; and the frequency of intracerebral hemorrhages differed significantly between group L and group S (p = 0.0105, p = 0.0075, and p = 0.0458, respectively). There were no significant differences in the frequencies of periprocedural hemorrhagic or ischemic events. Conversely, rebleeding after the initial treatment was significantly more common in group L than in group S (6.8% vs. 2.0%; p = 0.0372). The frequency of a modified Rankin Scale score of 0-2 at discharge was significantly lower (p = 0.0012) and the mortality rate was significantly higher (p = 0.0023) in group L than in group S. After propensity-score matching, there were no significant differences in complications and outcomes between the two groups. Rebleeding was more common in large aneurysm cases. However, propensity-score matching indicated that the outcomes of EM for aSAH may not be affected markedly by aneurysm size.

Volume embolization ratio of coiled cerebral aneurysms, does awake technique affect the results?

Background

Despite the great innovations in the neuroendovascular techniques and related materials, there are still notable percentages of recurrent cerebral aneurysms after aneurysm coiling. Aneurysm packing density is well known to affect the initial angiographic result of aneurysm embolization and has a crucial role in the stability of aneurysm obliteration. Although aneurysm coiling is commonly performed under general anesthesia, it could be performed under local anesthesia in certain circumstances.

Objective

The purpose of this study is to compare the volume embolization ratio (VER) and angiographic results of cerebral aneurysm embolization performed under local and general anesthesia.

Materials and methods

This is a retrospective cohort analysis of 20 consecutive cases of coiled cerebral aneurysms that were coiled under LA. Further, 15 cerebral aneurysm coil embolization cases have been collected from our data as matched control group.

Results

Embolization was performed under local anesthesia (Group A) in 20 patients (57.1%) and under general anesthesia (Group B) in 15 patients (42.9%). At the end of the procedure, control angiogram revealed complete obliteration in 13 patients (37.1%), while incomplete obliteration was detected in 22 patients (62.9%). The mean VER 27.9 ± 11.8 without a significant difference between both groups of the study as the VER of Group (A) was 26.05 ± 8.4 and that of Group B was 30.44 ± 15.2. Follow-up angiography at 1 year revealed complete obliteration in 17 (48.6%) of the coiled aneurysms, while incomplete obliteration was detected in 18 patients (51.4%).

Conclusions

Endovascular coiling of cerebral aneurysms under local anesthesia is a safe and feasible procedure without significant effects on the VER.

Radiological follow-up of endovascularly treated intracranial aneurysms: a survey of current practice in the UK and Ireland

PURPOSE

Due to the risk of intracranial aneurysm (IA) recurrence and the potential requirement for re-treatment following endovascular treatment (EVT), radiological follow-up of these aneurysms is necessary. There is little evidence to guide the duration and frequency of this follow-up. The aim of this study was to establish the current practice in neurosurgical units in the UK and Ireland.

METHODS

A survey was designed with input from interventional neuroradiologists and neurosurgeons. Neurovascular consultants in each of the 30 neurosurgical units providing a neurovascular service in the UK and Ireland were contacted and asked to respond to questions regarding the follow-up practice for IA treated with EVT in their department.

RESULTS

Responses were obtained from 28/30 (94%) of departments. There was evidence of wide variations in the duration and frequency of follow-up, with a minimum follow-up duration for ruptured IA that varied from 18 months in 5/28 (18%) units to 5 years in 11/28 (39%) of units. Young patient age, previous subarachnoid haemorrhage and incomplete IA occlusion were cited as factors that would prompt more intensive surveillance, although larger and broad-necked IA were not followed-up more closely in the majority of departments.

CONCLUSIONS

There is a wide variation in the radiological follow-up of IA treated with EVT in the UK and Ireland. Further standardisation of this aspect of patient care is likely to be beneficial, but further evidence on the behaviour of IA following EVT is required in order to inform this process.

Association of circumferential aneurysm wall enhancement with recurrence after coiling of unruptured intracranial aneurysms: a preliminary vessel wall imaging study

OBJECTIVE

Recent histopathological studies of unruptured intracranial aneurysms (UIAs) have confirmed that aneurysm wall enhancement (AWE) on MR vessel wall imaging (VWI) is related to wall degeneration with in vivo inflammatory cell infiltration. Therefore, pretreatment aneurysm wall status on VWI may be associated with recurrence after endovascular treatment.

METHODS

VWI with gadolinium was performed on 67 consecutive saccular UIAs before endovascular treatment between April 2017 and June 2021. The mean (range) follow-up period after treatment was 24.4 (6-54) months. AWE patterns were classified as circumferential AWE (CAWE), focal AWE (FAWE), and negative AWE (NAWE). The authors retrospectively investigated the relationship between aneurysm recurrence and AWE patterns, as well as conventional risk factors.

RESULTS

Sixty-seven patients with 67 saccular UIAs were eligible for the present study. AWE patterns were as follows: 10 CAWE (14.9%), 20 FAWE (29.9%), and 37 NAWE (55.2%). Follow-up MRA detected aneurysm recurrence in 18 of 69 cases (26.1%). Univariate analysis identified maximum diameter (mean ± SD 5.8 ± 2.2 mm in patients with stable aneurysms vs 7.7 ± 3.8 mm in those with unstable aneurysms, p = 0.02), aspect ratio (1.4 ± 0.5 vs 1.1 ± 0.4, p < 0.01), aneurysm location in posterior circulation (4.1% vs 27.8%, p < 0.01), volume embolization ratio (29.6% ± 7.8% vs 25.2% ± 6.1%, p = 0.02), and AWE pattern (p = 0.04) as significant predictive factors of recurrence. Among the 3 AWE patterns, CAWE was significantly more frequent in the unstable group, but no significant differences in stability of the treated aneurysms were observed with the FAWE and NAWE patterns. In multivariate logistic regression analysis, CAWE pattern (OR 14.2, 95% CI 1.8-110.8, p = 0.01) and volume embolization ratio ≥ 25% (OR 8.6, 95% CI 2.1-34.3, p < 0.01) remained as significant factors associated with aneurysm stability after coiling.

CONCLUSIONS

VWI before coiling provides novel insights into the stability of treated aneurysms. Aneurysms with the CAWE pattern on VWI before coiling may be less stable after treatment.

Endovascular treatment of pediatric basilar artery aneurysms: case series and literature review

PURPOSE

Pediatric basilar artery aneurysms are rare and challenging to treat. Microsurgical options and standard endovascular coiling are often undesirable choices for treatment of this pathology. Additional endovascular strategies are needed.

METHODS

Presentation, diagnosis, and management of pediatric basilar aneurysms were reviewed, with an emphasis on endovascular treatment strategies. Our case series of 2 patients was presented in detail, one treated with flow diversion and vessel sacrifice and one treated with stent-assisted coiling. An extensive review of the literation was performed to find other examples of pediatric basilar artery aneurysms treated with endovascular techniques.

RESULTS

Twenty-nine studies met inclusion criteria. Fifty-nine aneurysms in 58 patients were treated using endovascular techniques. Mortality rate was 10.3% (6/58) and a poor outcome (GOS 1-3) occurred in 15.5% (9/58). There were 4 reported recurrences requiring retreatment; however, only 46.5% of patients had reported follow-up of at least 1 year. 71.1% (42/59) were dissecting aneurysms.

CONCLUSION

Basilar artery aneurysms in the pediatric population are rare, commonly giant and fusiform, and often not amenable to microsurgical or coiling techniques. The surrounding vasculature, location, size, and morphology of the aneurysm along with the durability of treatment must be considered in treatment decisions. With proper patient selection, stent-assisted coiling and flow diversion may increase the durability and safety of endovascular treatment in this population.

Selection bias in patients proposed for neurosurgical versus endovascular treatment of aneurysms of the posterior communicating artery

BACKGROUND

Microsurgical clipping and endovascular coiling are viable treatment options for posterior communicating artery (PComA) aneurysms, but there are still major limitations to evidence-based decisions regarding standard-of-care treatment. In this study, we aimed at assessing potential selection biases that may influence our ability to extract conclusions about the comparative effectiveness or efficacy of the aneurysm treatment.

OBJECTIVE

To study the patient/aneurysm characteristics as possible biases in the option for endovascular or neurosurgical treatment of PComA aneurysms.

METHODS

A single-center, retrospective cohort study was performed, including all patients with treated PComA aneurysms with neurosurgical clipping or endovascular coiling between January 2010 and January 2021. Clinical and morphological data were collected from electronic records, and statistical analysis was performed.

RESULTS

A total of 64 patients was eligible for inclusion; 24 (37.5%) patients were proposed for neurosurgical treatment, while 40 (62.5%) for endovascular treatment; 10 patients (25%) crossed over to the clipping group whereas none crossed over to the coiling side. Actual treatment analysis showed significantly higher diameters of mother vessel (t-test, p = 0.034) and aneurysm neck (Mann-Whitney, p = 0.029) in the clipping group and higher aspect and dome-to-neck ratios in the endovascular group (Mann-Whitney, p = 0.008). A significantly higher vasospasm frequency was found in the clipping group but only in the intention-to-treat analysis (Chi-square, p = 0.032).

CONCLUSION

Significant morphological differences between effective endovascular and surgical groups and differences in intention-to-treat analysis may limit the validity of a direct comparison between treatment options and suggest the presence of a possible selection bias.

Endovascular coiling versus microsurgical clipping for ruptured intracranial aneurysms: a meta-analysis and systematic review

Background

The purpose of this analysis is to evaluate the current evidence with regard to the effectiveness and safety between coiling and clipping in patients with ruptured intracranial aneurysms (RIAs).

Methods

We performed a meta-analysis that compared clipping with coiling between July 2000 and September 2021. PubMed, EMBASE, and the Cochrane Library were searched for related articles systematically. And the treatment efficacy and postoperative complications were analyzed.

Results

We identified three randomized controlled trials and thirty-seven observational studies involving 60,875 patients with ruptured cerebral aneurysms. The summary results showed that coiling was related a better quality of life (mRS0-2; OR=1.327; CI=1.093–1.612; p<0.05), a higher risk of mortality (OR=1.116; CI=1.054–1.180; p<0.05), higher rate of rebleeding (RR=1.410; CI=1.092–1.822; p<0.05), lower incidence of vasospasm (OR=0.787; CI=0.649–0.954; p<0.05), higher risk of hydrocephalous (RR=1.143; CI=1.043–1.252; p<0.05), lower risk of cerebral infarction (RR=0.669; CI=0.596–0.751; p<0.05), lower risk of neuro deficits (RR=0.720; CI=0.582-0.892; p<0.05), and a lower rate of complete occlusion (OR=0.495; CI=0.280-0.876; p<0.05).

Conclusion

Coiling was significantly associated with a better life quality (mRS0-2), a lower incidence of postoperative complications, and a higher rate of mortality, rebleeding, hydrocephalous, and a lower rate of complete occlusion than clipping.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41016-022-00283-3.

Risk factors of recurrence after endovascular embolization of posterior communicating artery aneurysms

BACKGROUND AND OBJECTIVE

To determine the risk factors for recurrence after endovascular embolization of posterior communicating artery aneurysms (PcomA).

METHODS

We retrospectively analyzed a cohort of 163 patients harboring 172 PocmAs who were treated with endovascular embolization from January 2019 to December 2020. The patients were divided into recurrence and stable groups depending on outcome. Univariate and logistic regression analyses were performed to determine the potential risk factors of recurrence during follow-up.

RESULTS

Of the total 163 patients harboring 172 aneurysms, 107 were treated with simple coil occlusion and 65 were treated with stent-assisted coil embolization. There were significant differences in aneurysm sizes and use of non-stent-assisted coil embolizations between the groups (P < 0.05). The incidence of saccular aneurysm and Raymond grade were significantly higher in the recurrent group than in the stable group (P < 0.01). After variable selection, Raymond grade, aneurysm size, saccular aneurysm and non-stent-assisted coil embolization were included in further analysis. Binary logistic regression analysis revealed significant associations with non-stent-assisted coil embolization (P = 0.007), packing density (P < 0.001) and Raymond grades II (P < 0.001) and III (P = 0.002).

CONCLUSION

Non-stent-assisted coil embolization, as well as packing density and Raymond grades II grade III are associated with recurrence after endovascular treatment of PcomA.

Ultra-Short-Term Dual Antiplatelet Therapy in Treating Unruptured Brain Aneurysm With the Pipeline Flex-Shield Embolization Device

Ruptured cerebral aneurysms can cause significant morbidity and mortality. Endoluminal devices to treat aneurysms such as the Pipeline™ Flex Embolization Device with Shield Technology (PFES) (Medtronic, Dublin, Ireland) integrate phosphorylcholine on the surface of the device in order to reduce platelet adherence that causes periprocedural thromboembolic events and subsequent long-term intrastent stenosis. In addition to the Shield Technology, patients are commonly placed on dual antiplatelet therapy (DAPT) for six months to reduce thromboembolic events and subsequent long-term intrastent stenosis. There is a strong positive correlation between the length of DAPT use and bleeding. Here, we present a case of a 66-year-old female with a right supraclinoid internal carotid artery (ICA) aneurysm treated with a PFES who was placed on dual antiplatelet therapy for the first 31 days postoperative and subsequently maintained on aspirin (ASA) 81 mg monotherapy. At two months, a follow-up diagnostic cerebral angiogram showed complete occlusion of the aneurysm with a patent stent. Our case sets the stage for further research into the optimal length of dual antiplatelet therapy required in PFES to prevent short and long-term thromboembolic events. This report indicates that it may be safe for patients with PFES to intermittently halt the use of DAPT to manage bleeding complications or perform surgery.

Rabbit Elastase Aneurysm Model Mimics the Recurrence Rate of Human Intracranial Aneurysms following Platinum Coil Embolization

BACKGROUND AND PURPOSE

Intracranial aneurysms treated with coils have been associated with incomplete occlusion, particularly in large or wide-neck aneurysms. This study aimed to validate the accuracy of the rabbit elastase model in predicting aneurysm recurrence in humans treated with platinum coils.

MATERIALS AND METHODS

Elastase-induced saccular aneurysms were induced in rabbits and embolized with conventional platinum coils. The recurrence rates of aneurysms were retrospectively analyzed. Morphologic characteristics of aneurysms, angiographic outcomes, and histologic healing were evaluated.

RESULTS

A total of 28 (15.3%) of 183 aneurysms recurred. The aneurysm recurrence rate observed in this study (15.3%) is similar to those reported in multiple analyses of aneurysm recurrence rates in humans (7%-27%). The rate of recurrence was higher in aneurysms treated without balloon assistance (19/66, 28.8%) compared with those treated with balloon assistance (9/117, 7.7%). Aneurysms treated with balloon-assisted coiling had a lower recurrence rate (OR = 0.17; 95% CI, 0.05-0.47; P = .001) and higher occlusion rate (OR = 6.88; 95% CI, 2.58-20.37; P < .001) compared with those treated without balloon-assisted coiling. In this rabbit elastase-induced aneurysm model, packing density and aneurysm volume were weak predictors of aneurysm recurrence; however, the packing density was a good predictor of the occlusion rate (OR = 1.05; 95% CI, 1.02-1.10; P = .008).

CONCLUSIONS

The rabbit elastase aneurysm model may mimic aneurysm recurrence rates observed in humans after platinum coil embolization. Moreover, balloon assistance and high packing densities were significant predictors of aneurysm recurrence and occlusion.

Long-Term Follow-up of Aneurysms Treated With Hydrogel-Coated Coils Shows Progressive Thrombosis and Improvement in Raymond-Roy Classification

BACKGROUND

Coil embolization of aneurysms has been shown to be a safe and effective method of aneurysm treatment. Hydrogel-coated coils were developed as a hybrid embolization device to increase the packing density of a coil mass in an aneurysm and to reduce retreatment and rerupture rates. Previous studies have shown a benefit compared with bare metal coils.

OBJECTIVE

To present long-term follow-up of a cohort of patients treated with hydrogel-coated coils to better determine the effectiveness compared with bare platinum coils.

METHODS

Between January 2003 and April 2012, we identified patients with both ruptured and unruptured aneurysms coiled at our institution, using some portion of hydrogel-coated coils. Planned follow-up angiography was performed at 6 months, 18 months, and 5 years post-treatment. All imaging was independently adjudicated by a single physician at a separate institution. The results were scored with the modified Raymond-Roy Occlusion Classification.

RESULTS

A total of 145 patients with 153 treated aneurysms were included in the study analysis. Immediately after treatment, 49% of aneurysms were classified at Raymond-Roy Occlusion Classification I or II, which improved to 83% by 6 months. This percent plateaued at 18-month and 5-year follow-up, measuring 86% and 90%, respectively. The retreatment rate was 14% over the 5-year period, and there were no rerupture events captured.

CONCLUSION

Treatment of intracranial aneurysms with coil embolization using hydrogel-coated aneurysms shows evidence of progressive occlusion, particularly over the first 6 months of follow-up. The retreatment rate is comparable with historical data, and the rerupture rate is low.

In situ crosslinking temperature-responsive hydrogels with improved delivery, swelling, and elasticity for endovascular embolization

Endovascular embolization of cerebral aneurysms is a common approach for reducing the risk of often-fatal hemorrhage. However, currently available materials used to occlude these aneurysms provide incomplete filling (coils) or require a complicated, time-consuming delivery procedure (solvent-exchange precipitating polymers). The objective of this work was to develop an easily deliverable in situ forming hydrogel that can occlude the entire volume of an aneurysm. The hydrogel is formed by mixing a solution of a temperature-responsive polymer containing pendent thiol groups (poly(NIPAAm-co-cysteamine) or poly(NIPAAm-co-cysteamine-co-JAAm)) with a solution of poly(ethylene glycol) diacrylate (PEGDA). Incorporation of hydrophilic grafts of polyetheramine acrylamide (JAAm) in the temperature-responsive polymer caused weaker physical crosslinking, facilitated faster and more complete chemical crosslinking, and increased gel swelling. One formulation (30 wt % PNCJ20 + PEGDA) could be delivered for over 220 s after mixing, formed a strong and elastic hydrogel (G' > 6000 Pa) within 30 min and once set, maintained its shape and volume in a model aneurysm under flow. This gel represents a promising candidate water-based material utilizing both physical and chemical crosslinking that warrants further investigation as an embolic agent for saccular aneurysms.

Repeated Aneurysm Intervention

Over the past 25 years the endovascular treatment of cerebral aneurysms has gained preference in some countries over the traditional surgical procedures. The review part of the article clearly demonstrates that the clinical results of both modalities are similar and the difference is seen only in technical effectivity. Surgical techniques fail far less frequently than the endovascular ones. Incompletely occluded or growing aneurysms after the endovascular approach expose the patient to the risk of rebleeding with all possible consequences. Markedly repeated procedures are much more common for endovascularly treated aneurysms, again with all the risks.In the authors institution over the past 20 years, a total of 2032 aneurysms were treated. In 1263 endovascularly managed aneurysms the regrowth or inclomplete initial occlusion necessitated 159 repeated propcedures (12.6%). In surgical group the total of 27 aneurysms needed retreatment (3.5%). The difference is statistically significant. In nine patients in endovascular group the rebleeding was the reason for repeated procedures. No rebleeding was seen in the surgical group.This fact, also shown in the review part of the article, is important in patients counseling. Given the similar clinical results of both modalities the patient should be advised on the necessity of repeated follow-ups and of possible technical failure and eventual repeated procedure which is more likely if endovascular procedure is chosen.

Avenir® vs. AxiumTM Coils for the Treatment of Intracranial Aneurysms: Results of a Multicenter Randomized Controlled Trial With Short-Term Follow-Up

Purpose

Endovascular coil occlusion is a successful and rapidly evolving strategy used to treat patients who present with intracranial aneurysms. This study aimed to compare the safety and efficacy of the Avenir® and Axium^TM passive mechanically detachable coil systems.

Methods

A prospective, multicenter, randomized controlled study was carried out at ten medical centers from March 2018 to December 2019. A series of consecutive patients diagnosed with intracranial aneurysms were randomly assigned to undergo endovascular treatment with either the Avenir® or the Axium^TM mechanically detachable coil systems. The short-term outcomes from the two groups were compared with a focus on treatment efficacy and safety.

Results

A total of 162 and 161 patients were enrolled in the Avenir and Axium groups, respectively. The rate of successful coil detachment was 100% for the Avenir group and 99.38% for the Axium group. At the six-month follow-up visit, the overall aneurysm occlusion rate was 94.66% for the Avenir group and 96.95% for the Axium group (p > 0.05). We observed no statistically significant differences in clinical condition (as per the modified Rankin Scale) or the degree of aneurysm occlusion (as determined by digital subtraction angiography [DSA] and Raymond-Roy Occlusion Classification). Surgical complications were reported in 27 subjects in the Avenir group and 22 in the Axium group (p > 0.05). DSA performed at 6 months revealed complete aneurysm occlusion in 84 and 86% of patients in the Avenir and Axium groups, respectively.

Conclusion

We observed no significant short-term differences with respect to efficacy or safety when using either Avenir® or Axium^TM coils for the treatment of intracranial aneurysms.

Endovascular treatment of medium and large intracranial aneurysms with large volume coils: A single-center experience

Background:

Large volume coils are an alternative to conventional coils for the treatment of intracranial aneurysms. However, there are no published reports documenting occlusion and complication rates in medium and large intracranial aneurysms. Therefore, we present our results in this subgroup of aneurysms.

Methods:

A single-center, retrospective analysis of consecutive patients treated with Penumbra coils 400 in aneurysms ≥7 mm was performed. Demographics, aneurysm features, procedural details, intraoperative complications, clinical outcomes, and occlusion rates were analyzed.

Results:

Thirty-three patients were included for analysis, and a total of 33 intracranial aneurysms were analyzed. Mean age was 57.6 years (SD ± 12.4) and 85% of the patients were women. Large aneurysms represented 46% of cases. Paraclinoid (55%) followed by posterior communicating (30.3%) aneurysms was the most frequently treated. Ruptured and saccular aneurysms were found in 49% and 63% of the cases, respectively. The mean aneurysmal dimensions were 14.2 mm width, 11.9 mm length, 5.4 mm neck, and 2.4 dome-to-neck ratio. A dome-neck ratio <2 was identified in 39% of cases. The mean number of coils per aneurysm was 4.8. Immediate modified Raymond–Roy Grades 1, 2, and 3A were achieved in 15%, 21%, and 64%, respectively. Twenty-six patients were evaluated at a mean follow-up period of 11 months, with an adequate occlusion of 92% and a good clinical outcome (modified Rankin score ≤2) in 96% of patients.

Conclusion:

Endovascular treatment with PC400 coils is an effective and safe option for medium and large intracranial aneurysms with high occlusion rates, few complications, and good clinical outcomes at follow-up.

Endovascular Management of Hemorrhagic Stroke

Significant advances in endovascular neurosurgery tools, devices, and techniques are changing the approach to the management of acute hemorrhagic stroke. The endovascular treatment of intracranial aneurysms emerged in the early 1990s with Guglielmi detachable coils, and since then, it gained rapid popularity that surpassed open surgery. Stent-assisted coiling and balloon remodeling techniques have made the treatment of wide-necked aneurysms more durable. With the introduction of flow diverters and flow disrupters, many aneurysms with complex geometrics can now be reliably managed. Arteriovenous malformations and fistulae can also benefit from endovascular therapy by embolization using n-butyl cyanoacrylate (NBCA), Onyx, polyvinyl alcohol (PVA), and coils. In this article, we describe the role of endovascular treatment for the most common causes of intracerebral and subarachnoid hemorrhages, particularly ruptured aneurysms and vascular malformations.

Five-Years Angiographic Follow-Up of Wide-Neck Intracranial Aneurysms Treated With LEO Plus Stent

Background: This study aimed to evaluate the angiographic and clinical outcome, with an emphasis on long-term follow-up, of the LEO Plus stent for wide-neck intracranial aneurysms treated in a single center.

Methods: We retrospectively examined a prospectively maintained database of patients treated with LEO Plus devices between January 2004 and December 2016. Data regarding patient demographics, aneurysm characteristics, and technical procedures were analyzed. Angiographic and clinical findings were recorded during the procedure and followed up over a period of at least 5 years.

Results: We identified 101 patients with 116 aneurysms. In 16 patients, the stent could not safely be placed. Thus, a total of 97 LEO Plus devices were implanted in 97 aneurysms of 85 patients. Adverse events (acute and delayed) were observed in 21.6% of cases (17/85), and most were resolved (70.6%; 12/17). Moreover, 5 years after the procedure, total morbidity and mortality were 2.3% (2/85) and 3.5% (3/85), respectively. Long-term imaging follow-up showed complete occlusions, neck remnants, and residual aneurysms in 73.1% (57/78), 14.1% (11/78), and 12.8% (10/78) of cases, respectively.

Conclusions: Long-term results of treatment of brain aneurysms with LEO stent show high rates of adequate and stable occlusion over time, with acceptable morbidity and mortality.

Usefulness of Craniograms in Discriminating Coiled Intracranial Aneurysms Requiring Retreatment

While endovascular coil embolization has become one of the major therapeutic modalities for intracranial aneurysms, long-term imaging follow-up is required because of the higher rate of retreatment compared with surgical clipping. The purpose of this study was to show the usefulness of craniograms to discriminate coiled intracranial aneurysms that required retreatment. Under the study protocol approved by institutional review board, a retrospective review of the medical record was done regarding coil embolization for intracranial aneurysms performed between January 2014 and December 2018. Coil embolization performed as the initial treatment and followed up for more than 1 year without additional treatment, and those performed as retreatment after the initial coil embolization performed at our institution were recruited. Craniograms obtained just after the initial treatment were compared with those obtained just before the additional treatment in the retreated cases and compared with the latest ones in the non-recurrence cases. Correlation between the morphological changes in the coil mass on the craniograms and retreatments was evaluated. During the study period, 288 coil embolization procedures for intracranial aneurysms were performed. From these, 191 treatments that were followed up for more than 1 year without any additional treatments and 30 retreatments were included. Morphological change of the coil mass was observed in 4 of the 191 non-recurrence treatments and 26 of the 30 retreatments, which was significantly correlated with retreatments (p <0.001). Craniogram was a useful modality in following up the coiled intracranial aneurysms to detect those required retreatments.

Comparison of Pipeline Embolization and Coil Embolization for the Treatment of Large Unruptured Paraclinoid Aneurysms

The efficacy of flow diversion (FD) in the treatment of paraclinoid aneurysms has been established. The pipeline embolization device (PED) is one of the most commonly used FD devices. Coil embolization is also useful for treating paraclinoid aneurysms. This study aimed to compare the efficacy and safety of PED treatment and coil embolization for large unruptured paraclinoid aneurysms. This was a single-center, retrospective study of large unruptured paraclinoid aneurysms treated endovascularly between 2009 and 2019 (coil embolization between 2009 and 2015, and PED between 2015 and 2019). Cases with a follow-up period of less than 1 year and recurrence after coil embolization were excluded. The treatment outcomes between coil embolization and PED were compared. We investigated 45 patients with 45 large unruptured paraclinoid aneurysms treated by endovascular surgery in our institution. Twenty-four patients were treated with coil embolization and 21 with PED. In the PED group, the device cost was significantly lower (2,770.4 ± 699.5 vs. 1941.2 ± 552.8 [1000 yen], P = 0.03), procedure duration was significantly shorter (155.4 ± 66.7 vs. 95.1 ± 35.4 min, P <0.01), and the numbers of re-treatments were lower than those in the coil embolization group (41.7 vs. 14.3%, P = 0.05). Both PED and coil embolization were effective and safe for large unruptured paraclinoid aneurysms, and their treatment results were similar. The PED is more beneficial because of its lower cost, shorter procedure duration, and fewer retreatments, and is therefore more useful for the treatment of large unruptured paraclinoid aneurysms.

Propensity score-adjusted analysis on stent-assisted coiling versus coiling alone for ruptured intracranial aneurysms

Stent-assisted coiling (SAC) for ruptured intracranial aneurysms (RIAs) remains controversial due to an inherent risk of potential thromboembolic and hemorrhagic complications. We compared SAC and coiling alone for the management of RIAs using propensity score-adjustment. Sixty-four patients treated by SAC and 220 by stand-alone coiling were retrospectively reviewed and compared using inverse probability of treatment weighting (IPTW) with propensity scores. Functional outcome, procedure-related and overall complications and angiographic results were analyzed. Aneurysms treated by SAC had a larger diameter, a wider neck and were more frequently located at the posterior circulation. SAC had a higher risk for thromboembolic complications (17.2% vs. 7.7%, p = 0.025), however, this difference did not persist in the IPTW analysis (OR 1.2, 95% CI 0.7-2.3, adjusted p = 0.458). In the adjusted analysis, rates of procedural cerebral infarction (p = 0.188), ventriculostomy-related hemorrhage (p = 0.584), in-hospital mortality (p = 0.786) and 6-month favorable functional outcome (p = 0.471) were not significantly different between the two groups. SAC yielded a higher complete occlusion (80.0% vs. 67.2%, OR 3.2, 95% CI 1.9-5.4, p < 0.001) and a lower recanalization rate (17.5% vs. 26.1%, OR 0.3, 95% CI 0.2-0.6, p < 0.001) than stand-alone coiling at 6-month follow-up. In conclusion, SAC of large and wide-necked RIAs provided higher aneurysm occlusion and similar clinical outcome, when compared to stand-alone coiling.

Long-term Follow-up Results after Flow Diverter Therapy Using the Pipeline Embolization Device for Large or Giant Unruptured Internal Carotid Artery Aneurysms: Single-center Retrospective Analysis in the Japanese Population

Flow diverter (FD) therapy using Pipeline embolization device (PED) has become an important alternative to treat internal carotid artery (ICA) aneurysms. Herein, we report the long-term outcome for 3 years after FD therapy using PED for ICA aneurysms in Japan. The patients who underwent angiographical and/or clinical follow-up for 3 years after the FD therapy using PED of large or giant unruptured ICA aneurysms from December 2012 at our university hospital are the subjects of this study. We retrospectively reviewed the in- and outpatients’ medical charts, and written operative and radiological records. There were 84 patients with 90 aneurysms who could be clinically and/or angiographically followed up for 3 years. Of these, 7 aneurysms were only available for clinical follow-up. Of the remaining 83 aneurysms, 6 aneurysms had vessel occlusion due to stent thrombosis or parent artery occlusion, and 60 of the remaining 77 (77.9%) had complete occlusion. In multivariate analysis, older age (>70 years), wide neck, and non-adjunctive coiling contributed statistically significantly to incomplete occlusion. Of the 84 patients, 2 patients (2.4%) had delayed complications between 6 months and 3 years after the initial FD placement. Three patients (3.6%) had poor outcome due to postoperative major stroke complications, 2 of which were acute complications. The long-term results after FD therapy are good both angiographically and clinically. Endothelialization of the aneurysmal neck and intra-aneurysmal thrombosis contribute to complete occlusion. The primary reason for the somewhat low complete occlusion in Japan may be the patients are generally older.

Risk Factors for Recanalization after Coil Embolization

The aim of our study was to identify risk factors for recanalization 6 months after coil embolization using clinical data followed by computational fluid dynamics (CFD) analysis. Methods: Firstly, clinical data of 184 patients treated with coil embolization were analyzed retrospectively. Secondly, aneurysm models for high/low recanalization risk were generated based on ROC curves and their cut-off points. Afterward, CFD was utilized to validate the results. Results: In multivariable analysis, aneurysm filling during the first embolization was an independent risk factor whilst packing density was a protective factor of recanalization after 6 months in patients with aSAH. For patients with unruptured aneurysms, packing density was found to be a protective factor whilst the aneurysm neck size was an independent risk factor. Complex flow pattern and multiple vortices were associated with aneurysm shape and were characteristic of the high recanalization risk group. Conclusions: Statistical analysis suggested that there are various factors influencing recanalization risk. Once certain values of morphometric parameters are exceeded, a complex flow with numerous vortices occurs. This phenomenon was revealed due to CFD investigations that validated our statistical research. Thus, the complex flow pattern itself can be treated as a relevant recanalization predictor.

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.

Postoperative Clipping Status after a Pterional versus Interhemispheric Approach for High-Positioned Anterior Communicating Artery Aneurysms

OBJECTIVE

When treating high-positioned anterior communicating artery (ACoA) aneurysms, pterional-transsylvian and interhemispheric approaches are both viable options, yet comparative studies of these two surgical approaches are rare. Accordingly, this retrospective study investigated the surgical results of both approaches.

METHODS

Twenty-four patients underwent a pterional approach (n=11) or interhemispheric approach (n=13), including a unilateral low anterior interhemispheric approach or bifrontal interhemispheric approach, for high-positioned ACoA aneurysms with an aneurysm dome height >15 mm and aneurysm neck height >10 mm both measured from the level of the anterior clinoid process. The clinical and radiological data were reviewed to investigate the surgical results and risk factors of incomplete clipping.

RESULTS

The pterional patient group showed a significantly higher incidence of incomplete clipping than the interhemispheric patient group (p=0.031). Four patients (36.4%) who underwent a pterional approach showed a postclipping aneurysm remnant, whereas all the patients who experienced an interhemispheric approach showed complete clipping. In one case, the aneurysm remnant was obliterated by coiling, while follow-up of the other three cases showed the remnants remained limited to the aneurysm base. A multivariate analysis revealed that a pterional approach for a large aneurysm with a diameter >8 mm presented a statistically significant risk factor for incomplete clipping.

CONCLUSION

For high-positioned ACoA aneurysms with a dome height >15 mm and neck height >10 mm above the level of the anterior clinoid process, a large aneurysm with a diameter >8 mm can be clipped more completely via an interhemispheric approach than via a pterional approach.

Endoluminal flow diverters in the treatment of sidewall and bifurcation aneurysm: A systematic review and meta-analysis of complications and angiographic outcomes

BACKGROUND AND AIM

The use of endoluminal flow diversion in bifurcation aneurysms has been questioned due to the potential for complications and lower occlusion rates. In this study we assessed outcomes of endovascular treatment of intracranial sidewall and bifurcation aneurysms with flow diverters.

METHODS

In July 2020, a literature search for all studies utilizing endoluminal flow diverter treatment for sidewall or bifurcation aneurysms was performed. Data were collected from studies that met our inclusion/exclusion criteria by two independent reviewers and confirmed by a third reviewer. Using random-effects meta-analysis the target outcomes including overall complications (hematoma, ischemic events, minor ischemic stroke, aneurysm rupture, side vessel occlusion, stenosis, thrombosis, transient ischemic stroke, and other complications), perioperative complications, and follow-up (long-term) aneurysm occlusion were intestigated.

RESULTS

Overall, we included 35 studies with 1084 patients with 1208 aneurysms. Of these aneurysms, 654 (54.14%) and 554 (45.86%) were classified as sidewall and bifurcation aneurysm, respectively, based on aneurysm location. Sidewall aneurysms had a similar total complication rate (R) of 27.12% (95% CI, 16.56%-41.09%), compared with bifurcation aneurysms (R, 20.40%, 95% CI, 13.24%-30.08%) (p = 0.3527). Follow-up angiographic outcome showed comparable complete occlusion rates for sidewall aneurysms (R 69.49%; 95%CI, 62.41%-75.75%) and bifurcation aneurysms (R 73.99%; 95% CI, 65.05%-81.31%; p = 0.4328).

CONCLUSIONS

This meta-analysis of sidewall and bifurcation aneurysms treated with endoluminal flow diverters demonstrated no significant differences in complications or occlusion rates. These data provide new information that can be used as a benchmark for comparison with emerging devices for the treatment of bifurcation aneurysms.

First in Man Pilot Feasibility Study in Extracranial Carotid Robotic-Assisted Endovascular Intervention

BACKGROUND

Robotic-assistance in endovascular intervention represents a nascent yet promising innovation.

OBJECTIVE

To present the first human experience utilizing robotic-assisted angiography in the extracranial carotid circulation.

METHODS

Between March 2019 and September 2019, patients with extracranial carotid circulation pathology presenting to Houston Methodist Hospital were enrolled.

RESULTS

A total of 6 patients met inclusion criteria: 5 underwent diagnostic angiography only with robotic-assisted catheter manipulation, while 1 underwent both diagnostic followed by delayed therapeutic intervention. Mean age was 51 +/- 17.5 yr. Mean anesthesia time was 158.7 +/- 37.9 min, mean fluoroscopic time was 22.0 +/- 7.3 min, and mean radiation dose was 815.0 +/- 517.0 mGy. There were no technical complications and no clinical deficits postprocedure. None of the cases required conversion to manual neurovascular intervention (NVI).

CONCLUSION

Incorporating robotic technology in NVI can enhance procedural technique and diminish occupational hazards. Its application in the coronary and peripheral vascular settings has established safety and efficacy, but in the neurovascular setting, this has yet to be demonstrated. This study presents the first in human feasibility experience of robotic-assisted NVI in the extracranial carotid circulation.

Pivotal trial of the Neuroform Atlas stent for treatment of posterior circulation aneurysms: one-year outcomes

BACKGROUND

Stent-assisted coiling of wide-necked intracranial aneurysms (IAs) using the Neuroform Atlas Stent System (Atlas) has shown promising results.

OBJECTIVE

To present the primary efficacy and safety results of the ATLAS Investigational Device Exemption (IDE) trial in a cohort of patients with posterior circulation IAs.

METHODS

The ATLAS trial is a prospective, multicenter, single-arm, open-label study of unruptured, wide-necked, IAs treated with the Atlas stent and adjunctive coiling. This study reports the results of patients with posterior circulation IAs. The primary efficacy endpoint was complete aneurysm occlusion (Raymond-Roy (RR) class I) on 12-month angiography, in the absence of re-treatment or parent artery stenosis >50%. The primary safety endpoint was any major ipsilateral stroke or neurological death within 12 months. Adjudication of the primary endpoints was performed by an imaging core laboratory and a Clinical Events Committee.

RESULTS

The ATLAS trial enrolled and treated 116 patients at 25 medical centers with unruptured, wide-necked, posterior circulation IAs (mean age 60.2±10.5 years, 81.0% (94/116) female). Stents were placed in all patients with 100% technical success rate. A total of 95/116 (81.9%) patients had complete angiographic follow-up at 12 months, of whom 81 (85.3%) had complete aneurysm occlusion (RR class I). The primary effectiveness outcome was achieved in 76.7% (95% CI 67.0% to 86.5%) of patients. Overall, major ipsilateral stroke and secondary persistent neurological deficit occurred in 4.3% (5/116) and 1.7% (2/116) of patients, respectively.

CONCLUSIONS

In the ATLAS IDE posterior circulation cohort, the Neuroform Atlas Stent System with adjunctive coiling demonstrated high rates of technical and safety performance.Trial registration number https://clinicaltrials.gov/ct2/show/NCT02340585.

Endovascular treatment with the Enterprise stent versus the Neuroform or Low-Profile Visualized Intraluminal Support stent for unruptured aneurysms

Aim: To compare outcomes among patients undergoing endovascular treatment for unruptured intracranial aneurysm (UIA) with the Enterprise stent versus the Neuroform or Low-Profile Visualized Intraluminal Support (LVIS) stent. Patients & methods: Patients undergoing endovascular procedure for UIA were classified into Enterprise stent and Neuroform or LVIS stent group. Groups were propensity-score matched and generalized estimating equations were used for outcomes assessment. Results: There were no significant between-group differences in length of stay or mortality. The Enterprise group had significantly lower odds of UIA-related inpatient readmissions versus the Neuroform/LVIS group (odds ratio: 0.62; 95% CI: 0.42-0.91). Conclusion: Enterprise stent use was associated with significantly lower readmissions versus competitor stent, with no difference in other study outcomes.

[Unruptured asymptomatic brain aneurysms: modern approaches to the choice of surgical method and treatment outcomes]

BACKGROUND

In recent years, significant attention has been paid to preventive vascular neurosurgery. Treatment of unruptured asymptomatic brain aneurysms is one of the sections of this surgery.

OBJECTIVE

To evaluate treatment outcomes in patients with unruptured asymptomatic brain aneurysms who underwent treatment chosen on the basis of criteria adopted at the Burdenko Neurosurgery Center.

MATERIAL AND METHODS

There were 2814 unruptured asymptomatic brain aneurysms in 2334 patients for the period from 1995 to 2019.

RESULTS

Microsurgical operations for unruptured asymptomatic brain aneurysms were performed in 64.9% of cases, endovascular procedures - in 35.1% of patients. Endovascular operations were usually performed for ICA aneurysms and posterior aneurysms of circle of Willis. Microsurgical operations were mainly performed in patients with aneurysms of anterior and middle cerebral arteries. Favorable outcomes (GOS grade V-IV) were obtained in most patients (98.3%). Incidence of severe complications was similar in both groups, mortality rate was 0.3% and 0.4%, respectively.

CONCLUSION

Currently, there is a tendency towards annual increase in the number of surgeries for unruptured brain aneurysms. Anatomical and morphological characteristics of aneurysm should be considered to achieve favorable clinical results. At the same time, comprehensive analysis of each case and identification of individual risk factors will eliminate serious complications of surgical treatment.

Rapid temporary coiling of the parent artery for the management of intraprocedural aneurysm rupture

Intraprocedural rupture (IPR) of an intracranial aneurysm is the most feared complication of primary and stent-assisted coiling because it carries a high risk of morbidity and mortality. The endovascular strategy applied to control IPR depends on the cause of the rupture and stage of the procedure. Rupture during primary or stent-assisted coiling is traditionally managed with the use of continued packing, balloon microcatheter placement, or in rare cases, with parent artery sacrifice. In this technical note, we describe the use of temporary coiling of the parent artery to control IPR in three cases. Temporary parent artery coiling creates a subocclusive state, resulting in aneurysmal blood flow reduction without interruption of blood flow to the distal territory. Flow reduction combined with the thrombogenicity of the previously deployed coils results in hemostasis. In the cases presented here, IPR occurred during the late stage of coiling. In each case, parent artery coiling was performed along with heparin reversal. After confirmation of hemostasis, the coils were retrieved to restore normal blood flow. We demonstrate that the technique of temporary parent artery coiling may be a safe and effective option for the management of IPR during primary or stent-assisted coiling.

Risk Factors of Angiographic Recurrence After Endovascular Coil Embolization of Intracranial Saccular Aneurysms: A Retrospective Study Using a Multicenter Database

Background: Endovascular therapy of intracranial aneurysms has a high recurrence rate. This study aimed to evaluate the risk factors of recurrence after endovascular coil embolization of intracranial aneurysms.

Methods: From January 2014 to May 2015, 504 patients with 558 intracranial aneurysms who were treated by endovascular therapy were recruited from four high-volume centers. We used multivariate Cox proportional hazard regression to evaluate the risk factors associated with the angiographic recurrence of intracranial saccular aneurysms after endovascular coil embolization.

Results: Angiographic follow-up was available for 504 patients (558 aneurysms), with a mean duration of 11.42 months. Of the 558 aneurysms, 57 (10.2%) aneurysms showed recurrence. Aneurysm size (p = 0.028), therapy (non-stent assisted coiling or stent-assisted coiling) (p = 0.008), the Raymond scale (p = 0.040), aneurysm rupture status (p < 0.001), and packing density (p < 0.001) showed significant associations with angiographic follow-up outcome. A low packing density was independently associated with aneurysmal recurrence after multivariate Cox proportional hazard regression analysis (p < 0.001).

Conclusion: Endovascular treatment is effective for these lesions. Multiple factors could attribute to the aneurysmal recurrence after endovascular coil embolization. The low packing density is the independent risk factor for aneurysmal recurrence. These findings should be verified by larger multicenter and multi-population studies.