Flow Diversion for Intracranial Aneurysm Management: A New Standard of Care

Spontaneous delayed migration or shortening after pipeline embolization device treatment of intracranial aneurysm: incidence, management, and risk factors

BACKGROUND

Studies reporting spontaneous delayed migration or shortening (SDMS) after treatment with the Pipeline Embolization Device (PED) are limited. This study aimed to evaluate the incidence of SDMS after PED treatment, propose management strategies, and identify the risk factors contributing to its occurrence.

METHODS

We retrospectively reviewed consecutive patients with an intracranial aneurysm (IA) treated with PEDs at three institutions. SDMS was classified as type I or II based on whether the PED covered the aneurysm neck.

RESULTS

The total cohort comprised 790 patients. SDMS was identified in 24 (3.04%) patients. Eighteen of the 24 patients had type I SDMS and did not require retreatment, while the remaining six patients had type II SDMS and all received retreatment. Multivariate logistic regression showed that the difference between the proximal and distal parent artery diameters (DPAD) (adjusted OR 2.977; 95% CI 1.054 to 8.405; P=0.039) and device tortuosity index (DTI) (adjusted OR 8.059; 95% CI 2.867 to 23.428; P<0.001) were independent predictors of SDMS after PED treatment, while the difference in length (DL) (adjusted OR 0.841; 95% CI 0.738 to 0.958; P=0.009) and PED plus coiling (adjusted OR 0.288; 95% CI 0.106 to 0.785; P=0.015) were protective factors.

CONCLUSION

The incidence of SDMS after PED treatment of IA was 3.04%. For patients with type I SDMS with incomplete aneurysm occlusion we recommend continuous imaging follow-up while, for patients with type II SDMS, we recommend aggressive retreatment. The DPAD and DTI were independent risk predictors of SDMS after PED treatment, while the DL and PED plus coiling were protective factors.

Improvement of Visual Field Defects after Neuroembolization Treatment of Intracranial Aneurysms. Case Reports

PURPOSE

Intracranial aneurysms and their hemorrhagic and thromboembolic complications represent a serious nosological unit that significantly endangers those afflicted. They are mostly asymptomatic until rupture occurs. In two case reports, we present our observations of young patients with impaired vision and headaches, in whom we found the presence of intracranial aneurysms.

OBSERVATIONS

Presentation of two case reports of patients who came to our department with impaired vision and headaches. The patients underwent a complete eye examination at our center, including a visual field examination. Based on the results of the examination, they were referred for  an imaging examination of the brain, which revealed the presence of intracranial aneurysms. The patients were subsequently sent to the interventional neuroradiology center, where they underwent a noninvasive endovascular neuroembolization procedure with flow diverter implantation. We continued to monitor the patients after the procedure and document the examination results up to 1 year after the procedure.

CONCLUSIONS AND SIGNIFICANCE

Thanks to the fast detection, diagnosis, and management of both patients, we prevented the occurrence of aneurysm rupture, thus a life-threatening complication. After endovascular procedures with flow diverter implantation, we observed a significant improvement in visual acuity as well as perimetric findings in both patients. When intracranial aneurysms are found within a week of the onset of eye symptoms and treated within three months, defects in the visual fields improved in our two patients within 6-12 months, and in one of the two patients the defects almost completely disappeared.

Activation of BMP4-pSmad1/5 pathway impairs the function of VSMCs in intracranial aneurysms

Intracranial aneurysms (IAs) are characterized by abnormal dilatation of the cerebral vessels. Vascular smooth muscle cells (VSMCs) are implicated in maintaining vascular homeostasis. Disordered VSMCs are one of the most common causes for occurrence and development of IAs. The bone morphogenetic protein 4 (BMP4) signalling pathway is involved in regulating cell proliferation, apoptosis, and differentiation. This study aimed to investigate the effects of BMP4 on VSMCs and its underlying mechanisms. BMP4 was upregulated in the VSMCs of IAs and caused apoptosis of VSMCs through Smad1/5 phosphorylation. In addition, BMP4 overexpression significantly promoted the proliferation and migration of VSMCs and induced a phenotypic transformation from contractile to inflammatory. Our findings facilitate further understanding of the occurrence and development of IAs and provide a potential therapeutic target.

Poly(2-methoxyethyl acrylate) (PMEA) improves the thromboresistance of FRED flow diverters: a thrombogenic evaluation of flow diverters with human blood under flow conditions

BACKGROUND

Surface modification of flow-diverting stents has been explored to reduce thrombus-related complications that may arise under clinical use. This study investigated the thromboresistant properties of the flow redirection endoluminal device (FRED) X, a flow diverter treated with a copolymer of poly(2-methoxyethyl acrylate) (PMEA; X Technology).

METHODS

The performance of FRED, FRED X, and Pipeline Flex with Shield Technology (sPED) was evaluated in an in vitro blood loop model. Blood activation level was assessed by the concentration of thrombin-antithrombin complex (TAT), β-thromboglobulin (β-TG), and platelet count, and qualitatively by scanning electron microscopy (SEM). Cellular adhesion characteristics were measured using human aortic endothelial cells that were seeded on flat sheets mimicking the surface of FRED, FRED X, and sPED, and evaluated with fluorescence microscopy. Statistical comparisons were conducted using one-way analysis of variance (ANOVA) with Tukey post hoc tests.

RESULTS

FRED X, sPED, and control blood loops showed significantly reduced blood activation levels (TAT and β-TG) compared with FRED (p<0.01). Consequently, FRED showed a significant decrease in platelet count compared with FRED X, sPED, and control loops (p<0.01). SEM imaging showed the lowest accumulation of blood cell-like deposits on FRED X compared with sPED and FRED, while FRED had the highest accumulation. Endothelial cells adhered and were widely spread on X Technology-treated sheets, while minimal cell adhesion was observed on phosphorylcholine-treated sheets.

CONCLUSION

The X Technology surface modification of FRED X demonstrated superior thromboresistant properties over untreated FRED while maintaining comparable cellular adhesion. Taken together, these properties may help mitigate material-related thromboembolic complications.

Trends of Expanding Indications of Woven EndoBridge Devices for the Treatment of Intracranial Aneurysms: A Systematic Review and Meta-analysis

PURPOSE

Woven EndoBridge (WEB) was introduced for the endovascular therapy of wide-neck intracranial aneurysms. The safety and efficacy have been evaluated through several meta-analyses. However, these reviews did not cover the expanding indications in detail. Therefore, we aimed to show the changing trends for intracranial aneurysm treatment using the WEB device.

METHODS

A systematic review and meta-analysis was conducted with PubMed, Embase, and Cochrane databases. We searched for studies that reported baseline characteristics of aneurysms and the WEB devices, which had treated more than 20 aneurysms consecutively. The pooled proportions of aneurysm indications and used WEB device types were obtained. To evaluate the changing indications for the treated aneurysm size, including the neck diameter, a trend line and linear regression model was measured.

RESULTS

A total of 27 cohorts were included encompassing 1831 aneurysms treated with the WEB. A total of 86% were used in the four major locations as on-label indications (middle cerebral artery bifurcation; 34%, anterior communicating artery; 26%, basilar tip; 18%, internal carotid artery terminus; 7%). Among off-label indications, the most common location was the posterior communicating artery (8%), followed by the anterior cerebral artery including the pericallosal artery (6%). The median aneurysm size and neck diameter was 7 mm and 4.6 mm, respectively. The WEB device has been used for the treatment of smaller aneurysms than the initial indication. Also, the proportion for ruptured aneurysm treatment was increased up to 15%.

CONCLUSION

The mechanical and technical development of the WEB resulted in expanding the indications for the treatment of intracranial aneurysms. The off-label indications accounted for 14% in total and an increasing number of small aneurysms are treated with WEB devices. Moreover, the proportion for ruptured aneurysm treatment was currently increased up to 14% more than in the beginning.

Microcatheter-guided compartment packing of acutely ruptured complex intracerebral aneurysms (ARCIAs): Preliminary experience and technical note

Objective

We present our initial experience using the microcatheter-guided compartment packing (MCP) technique for endovascular embolization of acutely ruptured complex intracerebral aneurysms (ARCIAs) and evaluate the safety, feasibility, and efficiency of this technique.

Methods

This retrospective, single-center study included 28 patients who underwent coil embolization using the MCP technique for ARCIAs at our institution between January 2021 and January 2022. The MCP technique was the placement of microcatheters in different compartments within the aneurysm to deploy the coils simultaneously or sequentially. Patient demographics, aneurysm characteristics, procedural parameters, grade of occlusion, complications, and clinical results were analyzed. The clinical outcomes were evaluated with modified Rankin Scale (mRS) scores.

Results

Of the 28 patients successfully treated with the MCP technique, 24 (85.7%) aneurysms were considered as complete occlusions (Raymond I) based on the immediate postembolization angiogram results. Complications occurred in 2/28 treatments, including guidewire perforation with subarachnoid hemorrhage and cerebral vasospasm-related cerebral infarction. An angiography follow-up demonstrated complete occlusion in 25/28 aneurysms. Twenty-six (92.9%) patients had favorable 90-day outcomes (mRS 0-2) after the endovascular coil embolization.

Conclusion

The MCP technique is simple, safe, and effective, achieving good packing density and initial occlusion rate when used to treat ARCIAs.

Efficacy of pipeline embolization device vs. traditional coils in embolization of intracranial aneurysms: A systematic review and meta-analysis

Introduction

In recent years, the Pipeline embolization device (PED) has been widely used in the embolization of intracranial aneurysms, but there are some inconsistent findings on whether its efficacy and safety are superior to those of traditional coils embolization (coils alone, stent-assisted coils and balloon-assisted coils). The purpose of this meta-analysis was to evaluate the safety and efficacy of PED in intracranial aneurysm embolization by comparing with traditional coils.

Methods

We systematically searched PubMed, Embase, Web of Science, and The Cochrane Library databases for randomized controlled trials and observational studies (case-control studies and cohort studies) comparing the efficacy of PED with traditional coils in intracranial aneurysm embolization published before April 1, 2022. The endpoints observed in this meta-analysis were procedure-related intracranial hemorrhage, procedure-related intracranial ischemia, other procedure-related complications (e.g., aneurysm rupture, neurological impairment, etc.), retreatment rate, complete occlusion (100%) of the aneurysm at the last follow-up, and favorable functional outcome (MRS ≤ 2).

Results

A total of 10 studies with a total of 1,400 patients (PED group: 576 and Traditional coils: 824) were included in this meta-analysis. A comprehensive analysis of the included literature showed that the PED group had a higher rate of complete aneurysm occlusion [OR = 2.62, 95% Cl (1.94, 3.55), p &lt; 0.00001] and Lower re-treatment rate [OR = 0.20, 95% Cl (0.12, 0.34 p &lt; 0.00001)] compared with the traditional coil embolization group at the last follow-up. In terms of procedure-related intracranial hemorrhage [OR = 3.04, 95% Cl (1.08, 8.57), p = 0.04] and other procedure-related complications [OR = 2.91, 95% Cl (1.48, 5.57), p = 0.002], the incidence of PED was higher than that of the traditional coil embolization group. Moreover, in terms of favorable functional outcome [OR = 0.4, 95% Cl (0.22, 0.71), p = 0.002] of patients at the last follow-up, the PED group was lower than the traditional coil embolization group. There was no statistically significant between the two groups in terms of surgery-related intracranial ischemia complications [OR = 0.88, 95% Cl (0.47, 1.64), p = 0.68].

Conclusion

PED had higher rates of complete aneurysm occlusion and lower rates of aneurysm retreatment compared with traditional coils, but traditional coils was superior to the PED group in terms of procedure-related intracranial hemorrhage complication and other procedure-related complications (aneurysm rupture, neurological impairment), and favorable functional outcome (mRS ≤ 2). This result still needs to be further confirmed by additional large-sample, multicenter, prospective randomized controlled trials.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022325673.

Progressive volume reduction and long-term aneurysmal collapse following flow diversion treatment of giant and symptomatic cerebral aneurysms

Background

The primary goal of conventional endovascular and microvascular approaches is the clinical and radiological resolution of the symptomatic aneurysm-induced mass effect. This study assessed the volume changes and mass effect reduction due to sac shrinkage after treatment with flow diverter stents (FD) for unruptured cerebral aneurysms.

Methods

We analyzed retrospectively 36 symptomatic aneurysms that were larger or equal to 25 mm in diameter in patients treated at our center from January 2016 to April 2022. Radiological and clinical outcomes were analyzed, including aneurysmal volume changes and resolution of aneurysm-related symptoms.

Results

At 6 months, 25 aneurysms decreased in size, 2 remained unchanged, and 9 aneurysms demonstrated a post-treatment dimensional increase. At 12 months, 30 aneurysms showed a progressive radiological volume reduction. Either no change or negligible shrinkage was observed in the remaining six aneurysms. At 24 months, 32 aneurysms showed aneurysmal shrinkage by a mean 47% volume loss with respect to baseline. At the last follow-up, all 13 patients who had presented with third cranial nerve palsy showed improvements. Complete reversal of the pretreatment edematous changes was confirmed in all cases. The overall post-treatment complication rate was 8.3%, as 3 patients experienced non-fatal delayed rupture of their aneurysm. There was no mortality in this study.

Conclusion

Flow diversion could effectively induce progressive aneurysmal shrinkage and resolution of the mass effect associated with giant symptomatic cerebral aneurysms.

Dynamic interaction nursing intervention on functional rehabilitation and self-care ability of patients after aneurysm surgery

BACKGROUND

Nursing practices based on the dynamic interaction model have been shown to be superior to generic nursing practices. However, whether this model is effective in patients recovering from intracranial aneurysm surgery is not well studied.

AIM

To investigate the effect of nursing based on a dynamic interaction model on functional rehabilitation of patients after aneurysm surgery.

METHODS

A total of 86 cases in our hospital with intracranial aneurysm from April 2019 to April 2021, were selected and divided into the study group and the control group, with 43 patients in each group. The control group received routine nursing, and the research group received nursing intervention based on a dynamic interaction model. The daily living ability (activities of daily living, ADL), cognitive function (Simple Intelligent Mental State Scale, MMSE), quality of life (Generic Quality of Life Inventory-74, GQOL-74), self-care ability (Exercise of Self-Care Agency scale), incidence of complications, and nursing satisfaction were recorded before and after intervention.

RESULTS

Before intervention, ADL (52.09 ± 6.44), MMSE (18.03 ± 4.11), and GQOL-74 (53.68 ± 4.34) scores in the study group were not significantly different from those in the control group (ADL: 50.97 ± 7.32, MMSE: 17.59 ± 3.82, GQOL-74: 55.06 ± 3.98) (P > 0.05). After intervention, ADL (86.12 ± 5.07), MMSE (26.64 ± 2.66), and GQOL-74 (83.13 ± 5.67) scores in the study group were higher than those in the control group (ADL: 79.81 ± 6.35, MMSE: 24.51 ± 3.00, and GQOL-74: 77.96 ± 6.27) (P < 0.05). Before intervention, self-concept (17.46 ± 4.44), self-care skills (25.22 ± 4.20), self-care knowledge (22.35 ± 4.74), and self-care responsibility (15.06 ± 3.29) scores in the study group was similar to those in the control group (self-concept: 16.89 ± 5.53, self-care skills: 24.59 ± 4.46, self-care knowledge: 21.80 ± 3.61, and self-care responsibility: 14.83 ± 3.11) (P > 0.05). After the intervention, self-concept (26.01 ± 3.18), self-care skills (37.68 ± 6.05), self-care knowledge (45.56 ± 5.83), and self-care responsibility (22.01 ± 3.77) scores in the study group were higher than those in the control group (self-concept: 22.97 ± 3.46, self-care skills: 33.02 ± 5.65, self-care skills knowledge: 36.81 ± 5.54, and self-care responsibility: 17.97 ± 3.56 points) (P < 0.05). The incidence of complications in the study group (4.65%) was lower than that in the control group (18.60%) (P < 0.05). Nursing satisfaction in the study group (95.35%) was higher than that in the control group (81.40%) (P < 0.05).

CONCLUSION

Nursing intervention based on a dynamic interaction model can improve postoperative cognitive function, daily living ability, self-care ability, quality of life, and patient satisfaction, while reducing the risk of complications.

Efficacy and safety of flow diverters in posterior circulation aneurysms and comparison with their efficacy in anterior circulation aneurysms: A systematic review and meta-analysis

PURPOSE

We aimed to assess the efficacy and safety of flow-diverter stents (FDs) in the management of posterior circulation cerebral aneurysms and compare FD efficacy between anterior and posterior circulation aneurysms.

METHODS

We searched the PubMed, Scopus, Cochrane, and Web of Science databases for relevant studies through March 2020. Studies assessing FDs for posterior circulation aneurysms that included ≥20 treated aneurysms were included. Moreover, the studies compared FD efficacy between anterior and posterior circulation aneurysms were included. Data regarding angiographic aneurysmal occlusion, procedural complications, mortality, and morbidity were extracted and pooled in a random-effects meta-analysis model.

RESULTS

Fourteen studies with a total of 659 patients and 676 posterior circulation aneurysms were included. The pooled rate of aneurysmal occlusion at long-term angiographic follow-up was 78% [95% confidence interval (CI), 71-85]. The pooled rates of intraparenchymal hemorrhage, ischemia, and procedure-related mortality and neurological morbidity were 2%, 8%, 7%, and 6%, respectively. Complete occlusion occurred in 82.4% of the posterior circulation aneurysm subgroup and 77.5% of the anterior circulation aneurysm subgroup. The difference was not significant (relative risk 1.01; 95% CI, 0.86-1.19; p = 0.91). Regression analysis showed that elderly patients and females had higher morbidity.

CONCLUSION

Posterior circulation aneurysms can be effectively treated with FDs with comparable occlusion rates to those in anterior circulation aneurysms. However, periprocedural complications are not negligible.

Incidence of Neo-Intimal Hyperplasia in Anterior Circulation Aneurysms Following Pipeline Flow Diversion

INTRODUCTION

Flow diversion of the distal anterior circulation cerebral vasculature may be used for management of wide necked aneurysms not amenable to other endovascular approaches. Follow-up angiography sometimes demonstrates neo-intimal hyperplasia within or adjacent to the stent, however there is limited evidence in the literature examining the incidence in MCA and ACA aneurysms. We present our experience with flow diversion of the distal vasculature and evaluate the incidence of neo-intimal hyperplasia.

MATERIALS AND METHODS

Retrospective review of patients who underwent Pipeline embolization device (PED) treatment for ruptured and unruptured anterior circulation aneurysms.

RESULTS

A total of 251 anterior circulation aneurysms were treated by pipeline flow diversion, of which 175 were ICA aneurysms, 14 were ACA aneurysms and 18 were MCA aneurysms. 6-month follow-up angiography was available in 207 patients. The incidence of neo-intimal hyperplasia was 15.9%, 21.4%, and 61.1% in ICA, ACA, and MCA aneurysms, respectively. MCA-territory aneurysms developed neo-intimal hyperplasia at a significantly higher rate than aneurysms in other vessel territories. Rates of aneurysmal occlusion did not significantly differ from those patients who did not exhibit intimal hyperplasia on follow-up angiography.

CONCLUSION

In our experience, flow diversion of distal wide-necked MCA and ACA aneurysms is a safe and effective treatment strategy. The presence of neo-intimal hyperplasia at 6-month angiography is typically clinically asymptomatic. Given the statistically higher rate of neo-intimal hyperplasia in MCA aneurysms at 6-month angiography, we propose delaying initial follow-up angiography to 12-months and maintaining dual antiplatelet therapy during that time.

Management of Small Unruptured Intracranial Aneurysms: To Treat or Not to Treat?

Unruptured intracranial aneurysms measuring <7 mm in diameter have become increasingly prevalent due to advances in diagnostic imaging. The most feared complication is aneurysm rupture leading to a subarachnoid hemorrhage. Based on the current literature, the 3 main treatments for an unruptured intracranial aneurysm are conservative management with follow-up imaging, endovascular coiling, or surgical clipping. However, there remains no consensus on the best treatment approach. The natural history of the aneurysm and risk factors for aneurysm rupture must be considered to individualize treatment. Models including population, hypertension, age, size of aneurysm, earlier subarachnoid hemorrhage from a prior aneurysm, site of aneurysm score, Unruptured Intracranial Aneurysm Treatment Score, and advanced neuroimaging can assist physicians in assessing the risk of aneurysm rupture. Macrophages and other inflammatory modulators have been elucidated as playing a role in intracranial aneurysm progression and eventual rupture. Further studies need to be conducted to explore the effects of therapeutic drugs targeting inflammatory modulators.

Overview of Different Flow Diverters and Flow Dynamics

Over the past decade, flow diverter technology for endocranial aneurysms has seen rapid evolution, with the development of new devices quickly outpacing the clinical evidence base. However, flow diversion has not yet been directly compared to surgical aneurysm clipping or other endovascular procedures. The oldest and most well-studied device is the Pipeline Embolization Device (PED; Medtronic), recently transitioned to the Pipeline Flex (Medtronic), which still has sparse data regarding outcomes. To date, other flow diverting devices have not been shown to outperform the PED, although information comes primarily from retrospective studies with short follow-up, which are not always comparable. Because of this lack of high-quality outcome data, no reliable recommendations can be made for choosing among flow diversion devices yet. Moreover, the decision to proceed with flow diversion should be individualized to each patient. In this work, we wish to provide a comprehensive overview of the technical specifications of all flow diverter devices currently available, accompanied by a succinct description of the evidence base surrounding each device.

Single-Center Experience With the Bare p48MW Low-Profile Flow Diverter and Its Hydrophilically Covered Version for Treatment of Bifurcation Aneurysms in Distal Segments of the Anterior and Posterior Circulation

Background and Purpose: Flow diversion has profoundly changed the way aneurysms are treated. However, it conventionally requires dual antiplatelet medication and has yet been considered off-label use in the posterior circulation or within peripheral vessels of the anterior circulation. Here, we report our experience with the p48MW/p48MW hydrophilic coating (HPC) in the anterior and posterior circulation. This novel low-profile flow diverter is specifically designed for treatment of small peripheral vessels, and the p48MW HPC has an anti-thrombotic polymer coating, which allows application of a single antiplatelet function medication in conditions that expectably require further surgery.

Materials and Methods: Thirty-two patients were prospectively included. Twenty-six treatments were performed with one flow diverter, four required two overlapping flow diverters, one case demanded three overlapping flow diverters, and in one case, extensive dissecting aneurysm telescoping with eight flow diverters was necessary. Twenty-two complex bifurcation aneurysms were treated. Three months' follow-up was available for 14 patients.

Results: Deployment was uneventful in all cases. In four cases, undersizing was unavoidable and resulted in significant shortening of the flow diverter, which demanded implantation of further flow diverters to sufficiently treat the target aneurysm. Three flow diverters required balloon angioplasty for optimal wall approximation. All parent vessels remained patent. Available 3-month follow-up studies showed decreased influx or delayed washout in all aneurysms; none was occluded completely. There were no device-related clinical complications.

Conclusions: Implantation of the p48MW/p48MW HPC is safe and effective for treatment of distally located cerebral aneurysms. Considering the reported rates of ischemic complications associated with flow diversion of complex bifurcation aneurysms, the p48MW/p48MW HPC potentially provides increased safety for complex bifurcation aneurysms in the anterior and posterior circulation.

Advances in endovascular aneurysm management: flow modulation techniques with braided mesh devices

Flow diverters and flow disruption technology, alongside nuanced endovascular techniques, have ushered in a new era of treating cerebral aneurysms. Here, we provide an overview of the latest flow modulation devices and highlight their clinical applications and outcomes.

Endovascular Rescue Strategies for Nonopening of Pipeline Device: Report of Two Cases

We report two cases of rescue strategies for nonopening of Pipeline flow-diverter device for the treatment of intracranial aneurysm. The first patient, a 65-year-old female, presented with complaints of headache for 3 months and was found to have giant supraclinoid internal carotid artery (ICA) (ophthalmic segment) aneurysm. We planned endovascular partial coiling and flow-diverter placement for the treatment of ICA aneurysm. During the progressive deployment of PED, there was nonopening of Pipeline embolization device (PED) at its proximal end. We tried multiple attempts to navigate Marksman microcatheter over the PED delivery microwire and Echelon microcatheter over the Traxcess microwire across the pinched site, but we were not able to achieve success. After that, we tried opposite transcranial approach across prominent anterior communicating artery with the Synchro and Transcend microguidewire which finally resulted in the opening of the device; however, there was acute extravasation of dye on check angiogram. Thus, our technical success turned into disaster. The second patient, a 55-year-old female, presented with complaint of seizures for 3 months due to mass effect of cavernous sinus aneurysm. Pipeline Flex flow-diverter placement was done across the aneurysm neck. During the progressive deployment of device, there was nonopening of the mid and proximal segment of Pipeline Flex which was successfully managed by intra-Navien deployment of device followed by simultaneous push of Marksman microcatheter and pull of Navien catheter. In our case series, two rescue strategies were applied to successfully open the proximal constricted portion of Pipeline Flex; however, technical success in one case resulted in unmanageable disasters. Thus, transcranial rescue strategy for opening the constricted Pipeline Flex device should be cautiously used in our endovascular practice.

Delayed Stroke after Aneurysm Treatment with Flow Diverters in Small Cerebral Vessels: A Potentially Critical Complication Caused by Subacute Vasospasm

Flow diversion (FD) is a novel endovascular technique based on the profound alteration of cerebrovascular hemodynamics, which emerged as a promising minimally invasive therapy for intracranial aneurysms. However, delayed post-procedural stroke remains an unexplained concern. A consistent follow-up-regimen has not yet been defined, but is required urgently to clarify the underlying cause of delayed ischemia. In the last two years, 223 patients were treated with six different FD devices in our center. We identified subacute, FD-induced segmental vasospasm (SV) in 36 patients as a yet unknown, delayed-type reaction potentially compromising brain perfusion to a critical level. Furthermore, 86% of all patients revealed significant SV approximately four weeks after treatment. In addition, 56% had SV with 25% stenosis, and 80% had additional neointimal hyperplasia. Only 13% exhibited SV-related high-grade stenosis. One of those suffered stroke due to prolonged SV, requiring neurocritical care and repeated intra-arterial (i.a.) biochemical angioplasty for seven days to prevent territorial infarction. Five patients suffered newly manifested, transient hemicrania accompanying a compensatorily increased ipsilateral leptomeningeal perfusion. One treated vessel obliterated permanently. Hence, FD-induced SV is a frequent vascular reaction after FD treatment, potentially causing symptomatic ischemia or even stroke, approximately one month post procedure. A specifically early follow-up-strategy must be applied to identify patients at risk for ischemia, requiring intensified monitoring and potentially anti-vasospastic treatment.

Mid-term follow-up of staged bilateral internal carotid artery aneurysm treatment with Pipeline embolization

BACKGROUND

Endovascular treatment of large complex morphology aneurysms is challenging. High recanalization rates have been reported with techniques such as stent-assisted coiling and balloon-assisted coiling. Flow diverter devices have been introduced to improve efficacy outcomes and recanalization rates. Thromboembolic complications and in-device stenosis are certainly more worrisome when treatment of bilateral internal carotid arteries has been performed. This study aimed to report our experience with mid-term imaging follow-up of staged bilateral Pipeline embolization device placement for the treatment of bilateral internal carotid artery aneurysms.

METHODS

We reviewed the clinical, angiographic, and follow-up imaging data in all consecutive patients treated with bilateral internal carotid artery aneurysms who underwent elective Pipeline embolization.

RESULTS

Six female patients were treated, harboring a total of 13 aneurysms. Of these, 60% were asymptomatic. Diplopia and headache were the most common symptoms. The most common location was the paraclinoid segment (6/13), including by cavernous segment (4/13) and ophthalmic segment (2/13). Successful delivery of the device was achieved in 12 cases. Difficult distal access precluded the deployment of the device in one case. The treatment was always staged with at least eight weeks' difference between the two procedures. All aneurysm necks were covered completely. There were no periprocedural complications. Angiographic follow-up ranged between 3 and 12 months, and computed tomography angiogram follow-up ranged between 2 and 24 months. Complete aneurysm occlusion was achieved in all cases.

CONCLUSION

In our series, Pipeline deployment for the treatment of bilateral internal carotid artery aneurysms in a staged fashion is safe and feasible. Mid-term imaging follow-up showed permanent occlusion of all the treated aneurysms.

No differences in effectiveness and safety between pipeline embolization device and stent-assisted coiling for the treatment of communicating segment internal carotid artery aneurysms

BACKGROUND

Aneurysms arising from the communicating segment (C7) of the internal carotid artery (ICA) are one of the most frequent locations of intracranial aneurysms. Stent-assisted coiling (SAC) and flow diversion therapies are both endovascular strategies used for the treatment of ICA aneurysms occurring at the C7 segment.

OBJECTIVE

The aim of this study is to compare both methods' angiographic and functional outcomes, and procedural complications. To our knowledge, this is the first study to compare both modalities for aneurysms at this location.

METHODS

A retrospective review was performed of our prospectively collected database from 2008 until 2017 for patients treated with SAC and from 2013 until 2017 for patients treated with pipeline embolization devices (PEDs).

RESULTS

We identified 35 patients for this cohort with 38 aneurysms; 17 treated with SAC and 21 with PED. Mean age was 59 years, and 30 patients were female (86%). Complete occlusion at last follow-up occurred in 70.6% of patients in the SAC group and in 81% in the PED group (p = 0.45). Posterior communicating artery patency at last follow-up did not differ significantly between the two groups (94.1% vs 85.7%; p = 0.40). Good functional outcome at last follow-up (mRS 0-2) was achieved in 100% and 88.2% of patients, respectively. Additionally, there was no significant difference between the two groups for retreatment rates, procedural hemorrhagic, or thromboembolic complications.

CONCLUSION

SAC and PED are two equally efficacious modalities for endovascular treatment of ICA aneurysms arising at the communicating segment of the ICA.

On Flow Diversion: The Changing Landscape of Intracerebral Aneurysm Management

Uptake of flow-diverting technology is rapidly outpacing the availability of clinical evidence. Most current usage is off-label, and the endovascular community is nearer the beginning than the end of the learning curve, given the number of devices in development. A comprehensive overview of technical specifications alongside key outcome data is essential both for clinical decision-making and to direct further investigations. Most-studied has been the Pipeline Embolization Device, which has undergone a transition to the Pipeline Flex for which outcome data are sparse or heterogeneous. Alternative endoluminal devices do not appear to be outperforming the Pipeline Embolization Device to date, though prospective studies and long-term data mostly are lacking, and between-study comparisons must be treated with caution. Nominal technical specifications may be unrelated to in situ performance, emphasizing the importance of correct radiologic sizing and device placement. Devices designed specifically for bifurcation aneurysms also lack long-term outcome data or have only recently become available for clinical use. There are no major studies directly comparing a flow-diverting device with standard coiling or microsurgical clipping. Data on flow-diverting stents are too limited in terms of long-term outcomes to reliably inform clinical decision-making. The best available evidence supports using a single endoluminal device for most indications. Recommendations on the suitability and choice of a device for bifurcation or ruptured aneurysms or for anatomically complex lesions cannot be made on the basis of current evidence. The appropriateness of flow-diverting treatment must be decided on a case-by-case basis, considering experience and the relative risks against standard approaches or observation.

Nonsaccular aneurysms: A wide comparison between the four main types

Background:

The present study aims to present the most important considerations when it comes to patients features, clinical presentation, localization, morphology, pathogenesis, and the best treatment for each type of the nonsaccular aneurysms.

Methods:

We performed a literature review using PubMed. The search was limited to the studies published in English, from 2010 to 2017.

Results:

Data about the clinical presentation; the aneurysm pathogenesis, morphology, and localization; the patient features; and about the surgical or endovascular approach were analyzed for the four types of nonsaccular aneurysms presented.

Conclusion:

All types of nonsaccular aneurysms have a higher prevalence in young adults. Men are more affected by fusiform and mycotic aneurysms while women suffer more with blister-like aneurysms (BLAs). The mycotic and the BLAs affect more the anterior circulation while the fusiform affects more the posterior circulation. Mycotic and blister-like has as its major complication and clinical presentation the hemorrhage; however, the fusiform aneurysms usually present ischemia and/or mass effect. The reconstructive endovascular techniques for all types of nonsaccular aneurysms presented as the treatment with the best outcomes. Among this technique, the flow diversion presented good results in all types of aneurysms and it seems to promote the best outcomes.

Bailout Strategies and Complications Associated with the Use of Flow-Diverting Stents for Treating Intracranial Aneurysms

Background

Flow-diverting stents (FDS) have revolutionized the endovascular management of unruptured, complex, wide-necked, and giant aneurysms. There is no consensus on management of complications associated with the placement of these devices. This review focuses on the management of complications of FDS for the treatment of intracranial aneurysms.

Summary

We performed a systematic, qualitative review using electronic databases MEDLINE and Google Scholar. Complications of FDS placement generally occur during the perioperative period.

Key Message

Complications associated with FDS may be divided into periprocedural complications, immediate postprocedural complications, and delayed complications. We sought to review these complications and novel management strategies that have been reported in the literature.

Fusiform aneurysms: A review from its pathogenesis to treatment options

Background

This study aims to present the most important considerations when it comes to patients features, clinical presentation, localization, and morphology of the aneurysm and the treatments outcomes of the fusiform aneurysms.

Methods

We performed a literature review using PubMed. The search was limited to the studies published in English, from 2003 to 2017.

Results

The studies analyzed that showed data about the patient features, clinical presentation, the aneurysm localization, morphology, and pathogenesis didn't present much divergence. The surgical and the endovascular approach showed similar treatments outcomes. The reconstructive techniques seem to be safer than the deconstructive. The flow diversion is a technique that showed great results.

Conclusion

Most of the patients are men, younger than 50 years old, pediatric patients are the most affected. Surgical procedures still have an important place in this field. Reconstructive and deconstructive techniques are both effective; the reconstructive techniques are possibly safer than deconstructive techniques. The most important feature of an aneurysm to predict a bad prognose is to determine if the aneurysm is ruptured. The reconstructive EVT accompanied by dual antiplatelet after and before the procedure showed the best results to treat the basilar fusiform aneurysms. Deconstructive treatment including posterior inferior cerebellar artery occlusion should be considered.

Postoperative Anticoagulation After Neurologic Surgery

Management of anticoagulation and antiplatelet medications after neurosurgery can be complex, especially given that these patients have multiple medical comorbidities. In turn, neurosurgical patients are at high risk for the development of venous thromboembolism after surgery, so neurosurgeons must consider the use of pharmacologic prophylaxis. Developments in endovascular neurosurgery have produced therapies that require close management of antiplatelet medications to prevent postoperative complications. Any of these patient populations may need intrathecal access. This article highlights current strategies for managing these issues in the neurosurgical patient population.

Surpass Flow Diverter in the Treatment of Ruptured Intracranial Aneurysms-A Single-Center Experience

BACKGROUND

Use of a Surpass flow diverter (FD) device in the treatment of acutely ruptured aneurysm has not been well studied and reported in the literature.

METHODS

We retrospectively reviewed patients with subarachnoid hemorrhage who were treated by Surpass FD placement at our hospital between June 2016 and March 2018. Detailed analysis of medical records was performed to obtain patient age, gender, clinical history, Hunt and Hess grade, Fisher grade, results of radiographic and procedural details including technical success and complication, clinical outcome, and follow-up angiographic results.

RESULTS

Our search identified 16 patients with 16 aneurysms who were treated with Surpass FD, of which 13 aneurysms (81%) were in the anterior circulation and 3 (19%) were in the posterior circulation. Aneurysm size ranged from 1.1 to 16 mm, with a mean of 4 mm. The mean delay between subarachnoid hemorrhage and endovascular treatment was 5 days (range, 3-20 days). Only 1 Surpass FD was used in each patient, ranging in size from 3 × 25 mm to 4 × 50 mm. Fifteen patients (94%) achieved favorable clinical outcome (modified Rankin Scale score 0-1) at 3 months. One patient died of invasive fungal infection. Angiographic follow-up results were assessed by O'Kelly-Marotta grading scale in 15 surviving patients and showed a grade D result (no filling) in 13/15 aneurysms (87%) at 3 and 6 months.

CONCLUSIONS

A Surpass FD device is a feasible option for the treatment of ruptured intracranial aneurysms that are difficult to treat by conventional clipping and coiling; however, larger and comparative studies with long-term follow-up are needed to confirm its safety and efficacy.

Transient in-stent stenosis at mid-term angiographic follow-up in patients treated with SILK flow diverter stents: incidence, clinical significance and long-term follow-up

BACKGROUND

Little is known about in-stent stenosis (ISS) in patients with aneurysms treated with flow diverter (FD) stents. The reported incidence in the literature varies significantly.

OBJECTIVE

The aim of this study was to assess the incidence, severity, distribution, clinical significance, and possible predictors for ISS.

METHODS

Between July 2012 and June 2016 we retrospectively reviewed all patients treated with SILK FDs in our center. Only cases with short-term (4±2 months) and long-term (>1 year) follow-ups with digital subtraction angiograms were included. ISS was graded as mild (<25%), moderate (25-50%) or severe (>50%). The following predictors for ISS were assessed: gender, age, the presence of subarachnoid hemorrhage, aneurysm size, location, occlusion status, and post-stenting angioplasty.

RESULTS

Thirty-six patients met the inclusion criteria. At mid-term follow-up, ISS was observed in 16/36 patients (44%). Eleven patients (69%) had mild ISS, three (19%) moderate, and two (12%) severe ISS. ISS was diffuse in 11 patients (69%) and focal in five patients (31%). All patients were asymptomatic. Thirteen patients were maintained on dual antiplatelet therapy and three on aspirin alone. At long-term follow-up, complete ISS resolution was seen in 11 patients, improvement in three and worsening in two patients. No de novo ISS occurrence was observed. On univariate analysis there was no significant predictor for ISS.

CONCLUSIONS

Transient ISS after FD deployment is a common asymptomatic finding on mid-term angiographic follow-up. Complete resolution or improvement at long-term follow-up is seen in most patients who are maintained on dual antiplatelet therapy.

Rescue Therapy for Procedural Complications Associated With Deployment of Flow-Diverting Devices in Cerebral Aneurysms

Flow diverting devices (FDDs) have revolutionized the treatment of morphologically complex intracranial aneurysms such as wide-necked, giant, or fusiform aneurysms. Although FDDs are extremely effective, they carry a small yet significant risk of intraprocedural complications. As the implementation of these devices increases, the ability to predict and rapidly treat complications, especially those that are iatrogenic or intraprocedural in nature, is becoming increasingly more necessary.

Our objective in this paper is to provide a descriptive summary of the various types of intraprocedural complications that may occur during FDDs deployment and how they may best be treated. A systematic and qualitative review of the literature was conducted using electronic databases MEDLINE and Google Scholar. Searches consisted of Boolean operators “AND” and “OR” for the following terms in different combinations: “aneurysm,” “endovascular,” “flow diverter,” “intracranial,” and “pipeline.”

A total of 94 papers were included in our analysis; approximately 87 of these papers dealt with periprocedural endovascular (mainly related to FDDs) complications and their treatment; 7 studies concerned background material. The main categories of periprocedural complications encountered during deployment of FDDs are failure of occlusion, parent vessel injury and/or rupture, spontaneous intraparenchymal hemorrhage, migration or malposition of the FDDs, thromboembolic or ischemic events, and side branch occlusion

Periprocedural complications occur mainly due to thromboembolic events or mechanical issues related to device deployment and placement. With increasing use and expanding versatility of FDDs, the understanding of these complications is vital in order to effectively manage such situations in a timely manner.

The Effect of Placing Flow-Diverting Stents in Intracranial Collateral Arteries of Miniature Pig

BACKGROUND Flow-diverting stent (FDS) has been suggested as an effective intracranial aneurysm treatment. However, the effects of FDS on collateral branches of an aneurysm parent artery still remain unknown. Thus, the present study aimed to comprehensively evaluate the effects of placing a FDS in the intracranial collateral artery, using a miniature pig animal model. MATERIAL AND METHODS Ten healthy miniature pigs were included in the study: one pig was reserved as a control and the remaining nine pigs were placed in three experimental groups: FDS (i.e., Pipeline), LVIS, and Solitaier-AB stent groups. Pigs in the experimental groups were examined by cerebral angiography immediately after stent placement, followed by hemodynamic analyses. In addition, magnetic resonance imaging (MRI) of the brain of pigs in the experimental groups was performed to inspect the brain for obstruction and blood flow. Stents were examined for the growth of neointimas. RESULTS The results showed that neointimas, consisting of smooth muscle cells, collagenous fibers, and macrophages, were 0.67 mm thick on average and partially covered the stent wires. The thickness of neointimas in the FDS group was significantly higher than in the two conventional intracranial stent groups. There was no obvious obstruction identified in collateral arteries where the FDS was placed. CONCLUSIONS These results indicated that neointimas in collateral arteries of a miniature pig would be slightly thickened after one month of FDS placement; and FDS was shown to be safe for collateral arteries.