Prevalence and Clinical Predictors of Intracranial Hemorrhage Following Carotid Artery Stenting for Symptomatic Severe Carotid Stenosis.

OBJECTIVE: Hyperperfusion-induced intracranial hemorrhage (HICH) is the most frequent cause of death following carotid artery stenting (CAS). This study aimed to identify the presence of HICH after CAS and evaluate demographic and clinical variables associated with HICH. METHODS: We retrospectively reviewed clinical data of 446 consecutive patients with symptomatic severe carotid stenosis treated with CAS between November 2011 and August 2018. Good collateral compensation was defined as patency of the anterior communicating artery with well-developed bilateral A1 segments with or without posterior communicating arteries, according to the classification of Katano et al. Univariate and multivariate analyses were performed to determine whether there was a correlation between demographic and clinical variables and development of HICH. RESULTS: Stent placement was successful in all patients. Of 446 patients, 14 had HICH (3.14%); 1 of 14 (7.14%) patients displayed 80%-90% stenosis, and 13 patients had stenosis ≥90%. Thirteen patients (92.86%) had poor collateral circulation compensation. Two patients (14.3%) died despite rescue efforts. Age (≥70 years), degree of carotid artery stenosis (≥90%), and poor compensation of collateral circulation were associated with a higher frequency of HICH after CAS. Severe carotid artery stenosis (≥90%) was independently associated with HICH after stenting (odds ratio 13.633, P = 0.014). CONCLUSIONS: The incidence rate of HICH was 3.14%. Patients with severe carotid artery stenosis (≥90%) are at high risk for developing HICH after CAS. Further investigations are needed to better describe the contribution of other risk factors, including poor compensation of collateral circulation (especially anterior circulation).

Palliation of malignant dysphagia with a segmented self-expanding metal stent: A STROBE-compliant article.

ABSTRACT: Self-expanding metal stents (SEMSs) in different geometric shapes are an established palliative treatment for malignant tumors of the esophagus. Mechanical properties and stent design have an impact on patient comfort, migration rate, and removability. SEMS with a segmented design (segSEMS) have recently become available on the market, promising new biomechanical properties for stent placement in benign and malignant esophageal diseases. In this study, we evaluated recurrent dysphagia, quality of life as well as technical success and complications for segmented SEMS-implantation in a retrospective study in palliative patients with dysphagia caused by malignant tumors of the esophagus.Between May 2017 and December 2018, patients presented to the interdisciplinary department of endoscopy of the University Hospital Cologne underwent segmented SEMS placement for malignant dysphagia. Patient follow-up was evaluated, and complications were monitored. Quality of life and functional improvement were monitored using the EORTC QLQ-C30 and QLQ-OE18.A total of 20 consecutive patients (16 men, 4 women; mean age: 65.5, range: 46-82) participated in the study and were treated with 20 segSEMS in total. The success rate of stent placement was 100%. Stent migration occurred in 3 patients (15.0%). Insertion of segSEMS immediately lead to a 48.0% reduction of dysphagia in the first 2 months (P < .001). Pain while eating (odynophagia) could also be significantly reduced by 39.6% over the first 2 months (P < .001).Implantation of segSEMS is a feasible and effective treatment for dysphagia in palliative patients with malignant tumors of the esophagus, offering immediate relief of symptoms and gain of physical functions.

Pipeline Embolization Device for Intracranial Aneurysms in a Large Chinese Cohort: Complication Risk Factor Analysis.

During intracranial aneurysm embolization with the Pipeline embolization device (PED), ischemic and hemorrhagic complications have been observed in cases among Western populations. The postmarket multicenter registry study on the embolization of intracranial aneurysms with the PED in China, i.e., the PLUS study, was performed to assess real-world predictors of complications and functional outcomes in patients treated with the PED in a Chinese population. All patients with intracranial aneurysms who underwent embolization using the PED between November 2014 and October 2019 across 14 centers in China were included. The study endpoints included preoperative and early postoperative (< 30 days) functional outcomes (modified Rankin scale [mRS] scores) and complications related to PED treatment at early postoperative and follow-up time points (3-36 months). Multivariate analysis was performed to identify risk factors for complications. A total of 1171 consecutive patients (mean age, 53.9 ± 11.4; female, 69.6% [813/1171]) with 1322 aneurysms were included in the study. Hypertension, basilar artery aneurysms, and successful deployment after adjustment or unsuccessful device deployment were found to be independent predictors of ischemic stroke, while the use of the Flex PED and incomplete occlusion immediately after treatment were protective factors. An aneurysm size > 10 mm, distal anterior circulation aneurysms, and adjunctive coiling were found to be independent predictors of delayed aneurysm rupture, distal intraparenchymal hemorrhage, and neurological compression symptoms, respectively. The rate of PED-related complications in the PLUS study was similar to that in Western populations. The PLUS study identified successful deployment after adjustment or unsuccessful device deployment and the degree of immediate postoperative occlusion as novel independent predictors of PED-related ischemic stroke in a Chinese population. ClinicalTrial.gov Identifier: NCT03831672.

Nuisance bleeding complications in patients with cerebral aneurysm treated with Pipeline embolization device.

BACKGROUND: Patients with cerebral aneurysms treated with the Pipeline embolization device (PED) are maintained on dual antiplatelet therapy (DAPT) to prevent thromboembolic complications. Rates of minor, "nuisance" bleeding in these patients remain unknown. We sought to evaluate the frequency and factors associated with this bleeding and its effect on DAPT compliance. METHODS: We performed a multicenter retrospective cohort study on consecutive cases of intracranial aneurysms treated with PED. Patient characteristics, aneurysm characteristics, and bleeding complications were analyzed. Severity of bleeding was defined according to a previously published classification defining nuisance bleeding as easy bruising, bleeding from small cuts, petechia, and ecchymosis. RESULTS: 245 PED aneurysm procedures on 243 patients were retrospectively collected from three academic centers over a 4.25-year period. Sixty-seven patients (27%) had nuisance bleeds. Patients with a higher risk of nuisance bleeding were older (59.1±3.4 vs . 54.7±2.2, P=0.032). Patients with nuisance bleeds were more likely to have their DAPT regimen changed or dose lowered (29% vs 8.3%, P<0.001), were on DAPT for less time (10.0 months±2.60 vs. 14.6 months±1.95, P=0.005) and were more likely to have aneurysm occlusion at 6 months (P<0.001). Stepwise logistic regression found age predictive of a nuisance bleed (OR=1.033) CONCLUSIONS: Nuisance bleeding was a common complaint of PED-treated aneurysm patients maintained on DAPT. Increasing age and aneurysmal occlusion at 6 months were the only factors predictive of nuisance bleeds. Clinicians were more likely to adjust antiplatelet regimens or stop DAPT early given a nuisance bleed.

Clinical trial of carotid artery stenting using dual-layer CASPER stent for carotid endarterectomy in patients at high and normal risk in the Japanese population.

BACKGROUND: The dual-layer nitinol CASPER stent was designed to prevent plaque prolapse into its strut and periprocedural stroke. OBJECTIVE: To conduct a clinical trial for government approval of the device in patients at either high or normal risk for carotid endarterectomy (CEA). METHODS: Eligible patients had ≥50% symptomatic stenosis or ≥80% asymptomatic stenosis according to the North American Symptomatic Carotid Endarterectomy Trial methods (peak systolic velocity 130 and 230 cm/s on ultrasonography, respectively). The primary endpoint was the lack of major adverse events (MAEs), defined as death, stroke, and myocardial infarction within 30 days, and ipsilateral stroke within 1 year. The performance goal was set at 90.5%. MAE rates were also compared between the CEA high- and normal-risk groups. RESULTS: 140 carotid artery stenting procedures, including 40% of patients at high risk and 60% at normal risk for CEA, were performed in 13 institutes. MAEs occurred in two cases (one intraprocedural and one postprocedural stroke), and the MAE rate was 1.4%. The non-MAE rate was 98.6% according to Kaplan-Meier analysis, which was superior to the previously set performance goal. The deployment success, target lesion revascularization (TLR), in-stent restenosis, and cerebrovascular event rates were 99.3%, 2.4%, 8.5%, and 7.2%, respectively. The MAE rate in patients with normal CEA risk was 1.2%, which was similar to the high-risk CEA group, with no significant difference due to the small number of MAEs. CONCLUSIONS: The MAE rate following use of the CASPER stent was low (1.4%). The MAE, deployment success, TLR, in-stenosis, and cerebrovascular event rates were similar to those of previous reports.

Implementation of computer simulation to assess flow diversion treatment outcomes: systematic review and meta-analysis.

INTRODUCTION: Despite a decade of research into virtual stent deployment and the post-stenting aneurysmal hemodynamics, the hemodynamic factors which correlate with successful treatment remain inconclusive. We aimed to examine the differences in various post-treatment hemodynamic parameters between successfully and unsuccessfully treated cases, and to quantify the additional flow diversion achievable through stent compaction or insertion of a second stent. METHODS: A systematic review and meta-analysis were performed on eligible studies published from 2000 to 2019. We first classified cases according to treatment success (aneurysm occlusion) and then calculated the pooled standardized mean differences (SMD) of each available parameter to examine their association with clinical outcomes. Any additional flow diversion arising from the two common strategies for improving the stent wire density was quantified by pooling the results of such studies. RESULTS: We found that differences in the aneurysmal inflow rate (SMD -6.05, 95% CI -10.87 to -1.23, p=0.01) and energy loss (SMD -5.28, 95% CI -7.09 to -3.46, p<0.001) between the successfully and unsuccessfully treated groups were indicative of statistical significance, in contrast to wall shear stress (p=0.37), intra-aneurysmal average velocity (p=0.09), vortex core-line length (p=0.46), and shear rate (p=0.09). Compacting a single stent could achieve additional flow diversion comparable to that by dual-stent implantation. CONCLUSIONS: Inflow rate and energy loss have shown promise as identifiers to discriminate between successful and unsuccessful treatment, pending future research into their diagnostic performance to establish optimal cut-off values.

Long-term safety and efficacy of distal aneurysm treatment with flow diversion in the M2 segment of the middle cerebral artery and beyond.

BACKGROUND: Indications for flow diversion stent (FDS) treatment are expanding. However, there is still a lack of evidence for the long-term outcome in distally located aneurysms in the M2 segment of the middle cerebral artery (MCA) and beyond. METHODS: Consecutive subjects (from June 2013 to August 2020) with MCA aneurysms in the M2 segment or beyond treated with FDS were reviewed retrospectively. The primary endpoints for clinical safety were the absence of mortality, stroke event, re-rupture of the aneurysm, and worsening of clinical symptoms. The primary endpoint for treatment efficacy was complete/near-complete occlusion at follow-up after 12 months. RESULTS: 23 patients were identified: 7 aneurysms were located in the M2 segment of the MCA, 4 in the M2-M3 bifurcation, 2 in M3, 3 in M3-4 branching, and 2 in M4; 5 aneurysms were located in M2 with extension into the M1-M2 bifurcation. 13 aneurysms were of fusiform morphology, 8 sacculofusiform, and 2 saccular. 16 aneurysms were of highly suspected dissecting etiology. The median diameter of the parent vessel was 2.1 mm proximally and 2 mm distally. The median time of the follow-up was 30 months (range 16 months to 6 years). Complete/near complete occlusion was observed in 14/20 patients (70%) and one stable remodeling (5%) was seen at 12 months. 22 patients (95.6%) had an excellent clinical outcome (mRS 0-1) at 6 months. Technical challenges associated with the deployment of FDS occurred in 8.7% of cases. Severe complications, intraparenchymal hemorrhage and re-rupture of the aneurysm occurred in 2 patients (8.7%). CONCLUSION: Flow diversion of distally located aneurysms is technically feasible with low morbidity and mortality.

Distal anterior cerebral artery aneurysms treated with flow diversion: experience of a large-volume center and systematic review of the literature.

BACKGROUND: Evidence about the safety and the efficacy of flow diversion for distal anterior cerebral artery (DACA) aneurysms is scant. To provide further insight into flow diversion for aneurysms located at, or distal to, the A2 segment. METHODS: Consecutive patients receiving flow diversion for DACA aneurysms were retrieved from our prospective database (2014-2020). A PRISMA guidelines-based systematic review of the literature was performed. Aneurysm occlusion (O'Kelly-Marotta=OKM) and clinical outcomes were evaluated. RESULTS: Twenty-three patients and 25 unruptured saccular DACA aneurysms treated with flow diversion were included. Aneurysm size ranged from 2 mm to 9 mm (mean size 4.5 mm, SD ±1.6). Mean parent artery diameter was 1.8 mm (range, 1.2-3 mm, SD ±0.39). Successful stent deployment was achieved in all cases. Angiographic adequate occlusion (OKM C-D) at follow-up (14 months) was 79% (19/24 available aneurysms). No cases of aneurysm rupture or retreatment were reported. Univariate analysis showed a significant difference in diameter among aneurysms with adequate (4 mm) vs incomplete occlusion (7 mm) (P=0.006).There was one transient perioperative in-stent thrombosis, and three major events causing neurological morbidity: two stent thromboses (one attributable to the non-adherence of the patient to the antiplatelet therapy); and one acute occlusion of a covered calloso-marginal artery.Results from systematic review (12 studies and 107 A2-A3 aneurysms) showed 78.6% (95% CI=70-86) adequate occlusion, 7.5% (95% CI=3.6-14) complications, and 2.8%, (3/107, 95% CI=0.6-8.2) morbidity. CONCLUSIONS: Flow diversion among DACA aneurysms is effective, especially among small lesions. However, potential morbidity related to in-stent thrombosis and covered side branches should be considered when planning this strategy.

Lower complication rates associated with transradial versus transfemoral flow diverting stent placement.

BACKGROUND: Currently, there are no large-scale studies in the neurointerventional literature comparing safety between transradial (TRA) and transfemoral (TFA) approaches for flow diversion procedures. This study aims to assess complication rates in a large multicenter registry for TRA versus TFA flow diversion. METHODS: We retrospectively analyzed flow diversion cases for cerebral aneurysms from 14 institutions from 2010 to 2019. Pooled analysis of proportions was calculated using weighted analysis with 95% CI to account for results from multiple centers. Access site complication rate and overall complication rate were compared between the two approaches. RESULTS: A total of 2,285 patients who underwent flow diversion were analyzed, with 134 (5.86%) treated with TRA and 2151 (94.14%) via TFA. The two groups shared similar patient and aneurysm characteristics. Crossover from TRA to TFA was documented in 12 (8.63%) patients. There were no access site complications in the TRA group. There was a significantly higher access site complication rate in the TFA cohort as compared with TRA (2.48%, 95% CI 2.40% to 2.57%, vs 0%; p=0.039). One death resulted from a femoral access site complication. The overall complications rate was also higher in the TFA group (9.02%, 95% CI 8.15% to 9.89%) compared with the TRA group (3.73%, 95% CI 3.13% to 4.28%; p=0.035). CONCLUSION: TRA may be a safer approach for flow diversion to treat cerebral aneurysms at a wide range of locations. Both access site complication rate and overall complication rate were lower for TRA flow diversion compared with TFA in this large series.

Role of transcranial Doppler ultrasonography in assessing stenosis after flow diversion.

INTRODUCTION: Patients after implantation of flow diverters (FD) due to intracranial aneurysms require radiological and clinical follow-up in view of in-stent stenosis. The aim of the study was to evaluate transcranial Doppler ultrasonography (TCD) as an alternative to more invasive digital subtraction angiography in monitoring patients with FD. PATIENTS AND METHODS: Twenty-five patients after FD deployment due to internal carotid artery (ICA) aneurysms were reviewed. The degree stenosis found on TCD was compared with the results of catheter angiography. The TCD examinations were recorded from two sides at the extracranial ICA and the most proximal and distal segment of intracranial ICA. Analyzed TCD factors included: peak systolic blood flow velocity, end diastolic velocity, mean velocity, pulsatility index, and resistivity index. The side-to-side differences and ratios between particular TCD indices were calculated. RESULTS: The cumulative frequency of angiographic in-stent stenosis was 5 of 25 (20 %). The analysis showed that pulsatility index measured on the most proximal intracranial segment of ICA is a predictor for angiographic instent stenosis (AUC = 0.854; p = 0.04; 95 % CI 0.59-1.00). The threshold of pulsatility index separating stenosis and non-stenosis groups was 1.05 with a sensitivity of 50 % and a specificity of 100 %. As the cut-off threshold of PI was set 0.75 the sensitivity and specificity was 100 % and 16.7 %, respectively. CONCLUSIONS: The increased TCD-derived pulsatility index measured on the most proximal intracranial segment of ICA is associated with in-stent stenosis demonstrated on angiograms.

Utility of P2Y12 Reactive Unit Assessment on Ticagrelor in Cerebral Aneurysms Treated with Intracranial Stenting and Flow Diversion: Cohort Study and Case Report From Two Neurovascular Centers.

BACKGROUND: Dual antiplatelet therapy consisting of aspirin and clopidogrel is the standard of care for neurointerventional stenting and flow diversion. Platelet function testing has been increasingly performed to identify patients with a hypo- or hyper-response to clopidogrel. Ticagrelor has been a popular alternative antiplatelet agent for such patients. We assessed the role of platelet function testing in patients receiving ticagrelor and undergoing stenting or flow diversion. METHODS: The data from patients who had undergone stent-assisted coiling or Pipeline flow diversion of a cerebral aneurysm with ticagrelor therapy at any point during their treatment course from May 2017 to August 2019 at a single academic institution in the United States were retrospectively reviewed. Platelet function testing was used to determine the P2Y12 reactive units (PRUs), and the results were correlated with the procedural complications. RESULTS: A total of 28 patients with 29 aneurysms were treated while receiving ticagrelor. Of the 29 aneurysms, 16 (55.2%) were treated with flow diversion and 13 (44.8%) with stent-assisted coiling. Four thromboembolic complications (13.8%) and no hemorrhagic complications developed. Of the 8 patients with ≥1 PRU value >100, 4 (50%) had experienced a thromboembolic complication. The patients without a PRU value >100 did not experience any complications. CONCLUSION: A risk of thromboembolic complications exists for patients receiving ticagrelor, which correlated with the PRUs in the present preliminary study. The findings from the present study suggest that the safe PRU range for patients receiving ticagrelor should be shifted to 0-100, which is lower than that of clopidogrel, thought to be 60-210. Further validation of the optimal PRU range for patients receiving ticagrelor is necessary.

Understanding the effect of effective metal surface area of flow diverter stent's on the patient-specific intracranial aneurysm numerical model using Lagrangian coherent structures.

The effective metal surface area (EMSA) of flow diversions plays an essential role in the occlusion mechanism inside the aneurysm since the value of EMSA determines the amount of blood flow into the aneurysm sac. In the present study, three different models of a flow diverter stent, namely FRED 4017, FRED 4038, and FRED 4539, were virtually placed at the aneurysm neck of a 52-years-old female patient to identify the effect of EMSA on stagnation region formation inside the aneurysm sac. Lagrangian coherent structures (LCSs), hyperbolic time, and particle tracking analysis were employed to the velocity vectors obtained from computational fluid dynamics (CFD). It is noticed that use of FRED 4017 stent with 0.42 EMSA value caused nearly 40% of the weightless blood flow particles (more than FRED 4038 and FRED 4539) to stay inside the aneurysm while only 0.35% of the blood flow was remaining inside the aneurysm sac when no stent was placed into the aneurysm site. Furthermore, hyperbolic time computations illustrated the formation of stagnation fluid flow zones that can be associated with the residence time of the blood flow particles. Lastly, the results of hyperbolic time analysis are in good agreement with digital subtraction angiography (DSA) images taken in the clinic a few minutes after a FRED 4017 implantation.

Flow modification on the internal carotid artery bifurcation region and A1 segment after M1-internal carotid artery flow diverter deployment.

BACKGROUND: Clinical and hemodynamic consequences of flow diverters extending from the M1 to the internal carotid artery (ICA), covering the A1 segment, have rarely been investigated. We aimed to provide angiographic and clinical data about flow modifications on the covered A1. METHODS: Consecutive patients receiving M1-ICA flow diverters for unruptured aneurysms were collected from our prospective database (2014-2020). RESULTS: 42 A1 arteries covered with a single device were studied. All patients had an angiographic detected contralateral flow from the anterior communicating artery (AcomA). Immediately after flow diversion, 20 (47.6%) covered A1 showed slow flow. During a mean angiographic follow-up of 14 months, 13 (31%) and 22 (52.3%) A1 arteries were occluded and narrowed, respectively. Flow changes were asymptomatic in all cases. Vascular risk factors, sex, oversized compared with not oversized stents, immediate A1 slow flow, age, diameter of the A1, length of follow-up, and platelet inhibition rate were tested as prognosticators of A1 occlusion. Length of the angiographic follow-up was the only predictor of A1 occlusion (p=0.005, OR=3, CI=1.4 to 6.7). There were two device related ischemic events with a 2.3% rate of morbidity (one basal ganglia infarct after coverage of the M1 perforators and one transient acute instent thrombosis). CONCLUSIONS: Covering the A1 segment during M1-ICA flow diversion seems relatively safe, if the contralateral flow is assured by the AcomA. Approximately 31% and 52% of the covered A1 showed asymptomatic occlusions and narrowing, respectively. The likelihood of flow modification was proportional to the length of follow-up. Morbidity associated with flow diversion in the ICA terminus region was 2.3%.

How safe and effective are flow diverters for the treatment of unruptured small/medium intracranial aneurysms of the internal carotid artery? Meta-analysis for evidence-based performance goals.

BACKGROUND: The objective of this meta-analysis was to establish safety and effectiveness benchmarks for endovascular therapy of unruptured small-to-medium internal carotid artery (ICA) aneurysms using flow diverters. METHODS: A systematic literature review and subsequent meta-analysis were performed using best research methods. Studies of any design with at least 10 patients treated with flow diverters for predominantly (≥90%) unruptured small/medium ICA aneurysms and ≥6 month follow-up were included. The primary effectiveness endpoint was complete aneurysm occlusion rate at 12 months. The primary safety endpoint was a composite measure of cumulative events that could indicate a stroke or neurologic death: any death, stroke, intracranial hemorrhage, or worsening on the modified Rankin Scale. RESULTS: 41 studies (2614 patients) met eligibility criteria for the meta-analysis. The core lab adjusted complete occlusion rate was 74.9% (95% CI 69.6% to 79.8%) at 12 months for studies using any flow diverter. With an aim of generating performance goals for a US Investigational Device Exemption (IDE) study, a pre-specified analysis was conducted using only studies with flow diverters commercially available in the USA. In this cohort, 12 month complete occlusion was 74.6% (95% CI 66.8% to 81.7%). The primary safety event rate for flow diverters commercially available in the USA was 7.8% (95% CI 4.8% to 11.4%). CONCLUSIONS: The treatment of small and medium-sized aneurysms with flow diverters is effective in achieving curative reconstruction in most cases and is associated with low rates of morbidity and mortality. This meta-analysis informs robust performance goals for evaluating new flow diverters in small/medium unruptured carotid aneurysms.

Endosaccular Flow Disruption: A New Frontier in Endovascular Aneurysm Management.

Flow modification has caused a paradigm shift in the management of intracranial aneurysms. Since the FDA approval of the Pipeline Embolization Device (Medtronic, Dublin, Ireland) in 2011, it has grown to become the modality of choice for a range of carefully selected lesions, previously not amenable to conventional endovascular techniques. While the vast majority of flow-diverting stents operate from within the parent artery (ie, endoluminal stents), providing a scaffold for endothelial cells growth at the aneurysmal neck while inducing intra-aneurysmal thrombosis, a smaller subset of endosaccular flow disruptors act from within the lesions themselves. To date, these devices have been used mostly in Europe, while only utilized on a trial basis in North America. To the best of our knowledge, there has been no dedicated review of these devices. We therefore sought to present a comprehensive review of currently available endosaccular flow disruptors along with high-resolution schematics, presented with up-to-date available literature discussing their technical indications, procedural safety, and reported outcomes.

Endovascular management of acute postprocedural flow diverting stent thrombosis.

INTRODUCTION: Postprocedural thrombosis is a rare complication after flow diverting stent (FD) implantation for aneurysm treatment with few reported cases in the literature. Management strategies and outcomes associated with this complication have not been reported. METHODS: A multicenter retrospective series of cases of acute postprocedural FD thrombosis were compiled and prevalence was calculated based on procedural volumes over a 7 year period. Acute postprocedural FD thrombosis was defined as the development of neurologic deficit with angiographic imaging demonstrating acute thrombus within the index FD stent at least 2 hours following completion of the implantation procedure. RESULTS: A total of 10 cases of postprocedural thrombosis were identified at five participating centers among a total of 768 patients treated (prevalence 1.3%). Thrombosis occurred a median of 5.5 days after implantation (range 0-83 days). 9/10 patients underwent emergent angiography with intent to perform endovascular reperfusion. A variety of different endovascular treatments were used, including aspiration thrombectomy, retrievable stent thrombectomy, balloon angioplasty, and intra-arterial thrombolytic infusion, without any procedural complications. There were no instances of FD migration, stent kinking, or aneurysm rupture. 90% of patients achieved Thrombolysis in Cerebral Infarction 2B or greater revascularization. Favorable clinical outcomes (modified Rankin Scale score of 0-2) at 3 months were achieved in 88% of patients. CONCLUSION: Acute postprocedural thrombosis of an FD is a rare complication that occurs in approximately 1-2% of patients after aneurysm treatment. Patients presenting with acute postprocedural FD thrombosis should be aggressively managed using large vessel occlusion thrombectomy techniques, as good angiographic and clinical outcomes are possible.

Prospective study on embolization of intracranial aneurysms with the pipeline device: the PREMIER study 1 year results.

BACKGROUND: Preliminary clinical studies on the safety and efficacy of the pipeline embolization device (PED) for the treatment of small/medium aneurysms have demonstrated high occlusion rates with low complications. OBJECTIVE: To evaluate the safety and effectiveness of the PED for treatment of wide necked small and medium intracranial aneurysms. METHODS: PREMIER is a prospective, multicenter, single arm trial. Patients were treated with the PED for unruptured wide necked aneurysms, measuring ≤12 mm along the internal carotid artery or vertebral artery, between July 2014 and November 2015. At 1 year post-procedure, the primary effectiveness endpoint was complete occlusion (Raymond grade 1) without major parent vessel stenosis (≤50%) or retreatment, and the primary safety endpoint was major stroke in the territory supplied by the treated artery or neurologic death. RESULTS: A total of 141 patients were treated with PEDs (mean age 54.6±11.3 years, 87.9% (124/141) women). Mean aneurysm size was 5.0±1.92 mm, and 84.4% (119/141) measured <7 mm. PED placement was successful in 99.3% (140/141) of patients. Mean number of PEDs implanted per patient was 1.1±0.26; a single PED was used in 92.9% (131/141) of patients. At 1 year, 97.9% (138/141) of patients underwent follow-up angiography with 76.8% (106/138) of patients having met the study's primary effectiveness endpoint. The combined major morbidity and mortality rate was 2.1% (3/140). CONCLUSIONS: Treatment of wide necked small/medium aneurysms with the PED results in high rates of complete occlusion without significant parent vessel stenosis and low rates of permanent neurologic complications. TRIAL REGISTRATION: NCT02186561.

Outcome of intracranial flow diversion according to the antiplatelet regimen used: a systematic review and meta-analysis.

BACKGROUND: Thromboembolic complications are not uncommon in patients undergoing neurointerventional procedures. The use of flow diverting stents is associated with higher risks of these complications despite current dual antiplatelet regimens. OBJECTIVE: To explore contemporary evidence on the safety of emerging dual antiplatelet regimens in flow diverting stenting procedures. METHODS: We performed a systematic review and meta-analysis to identify relevant articles in electronic databases, and relevant references. Studies reporting the complications and mortality of flow diverting stenting procedures using acetyl salicylic acid (ASA) + ticagrelor or ASA + prasugrel compared with ASA + clopidogrel were included. RESULTS: Of 452 potentially relevant studies, we identified 49 studies (2526 patients) which reported the safety of ticagrelor or prasugrel for pooled analysis, and five studies (1005 patients) for meta-analysis. The pooled overall mortality in all studies was 2.14%, ischemic complications 6.89%, and hemorrhagic complications 3.68%. The use of ticagrelor or prasugrel was associated with a lower risk of mortality compared with clopidogrel (RR=4.57, 95% CI 1.23 to 16.99; p=0.02). Considering ischemic events, ASA + clopidogrel was as safe as ASA + prasugrel (RR=0.55, 95% CI 0.11 to 2.74; p=0.47) and ASA + ticagrelor (RR=0.74, 95% CI 0.32 to 1.74; p=0.49). ASA +ticagrelor was not associated with a higher risk of hemorrhagic complications (RR=0.92, 95% CI 0.27 to 3.16; p=0.89). CONCLUSIONS: Evidence suggests that dual antiplatelet regimens including ticagrelor or prasugrel are safe for patients undergoing flow diversion procedures. Regimens using ticagrelor were associated with better survival than those using clopidogrel in the included studies.

Safety and Efficacy of Bilateral Flow Diversion for Treatment of Anterior Circulation Cerebral Aneurysms.

BACKGROUND: Nearly 20% of individuals with an aneurysm will have multiple aneurysms-these individuals are at increased risk of subarachnoid hemorrhage. Treatment of bilateral aneurysms with flow diverters (FDs), or Pipeline embolization device, has not yet been established as an effective therapy. We evaluated the safety and efficacy of a 2-stage treatment of bilateral aneurysms with Pipeline embolization devices placed 6 months apart. METHODS: We performed a retrospective review to analyze the clinical and angiographic outcomes of 16 individuals with bilateral aneurysms treated with 2-stage flow diversion at a tertiary referral center from January 2010 to July 2018. RESULTS: Of the 16 patients with 33 aneurysms treated with bilateral flow diversion, 1 had 2 aneurysms treated with a single FD on the contralateral side. The aneurysms treated were ophthalmic, superior hypophyseal, posterior communicating, or cavernous segment aneurysms, with an average size of 6.5 mm. No major complications, such as in-stent stenosis, thromboembolic events, distal intraparenchymal hemorrhage, rerupture, stent migration, or neurological death, were recorded. All the patients had good functional outcomes. At the 24-month follow-up examination, 81% of aneurysms showed complete occlusion. No aneurysm required repeat treatment. CONCLUSIONS: The results from the present study have demonstrated that 2-stage treatment of bilateral aneurysms with FDs is both safe and efficacious. The timing of contralateral FD stent placement is critical. We found that 6 months allows for adequate neurological recovery and stent endothelialization.

Predictors of Clinical Outcome After Treatment of Intracranial Aneurysms with the Pipeline Embolization Device.

BACKGROUND: Flow-diverting stents have revolutionized the endovascular treatment of intracranial aneurysms. The purpose of this study is to identify predictors of adverse outcomes associated with the pipeline embolization device (PED). METHODS: A retrospective analysis of all patients treated with PED at a single high-volume center from January 2014 to September 2018. Patient outcomes, neurologic morbidity/mortality, and other clinical variables were analyzed. RESULTS: We treated 204 aneurysms in 170 patients with PED. Mean length of follow-up was 11 months. Most (181) aneurysms (89%) were located in the anterior circulation, and 23 (11%) were found in the posterior circulation. Most aneurysms were saccular (82%), followed by fusiform (11%), blister (4%), and dissecting pseudoaneurysms (3%). Mean aneurysm size was 8.2 + 5.7 mm with 145 (71%) small aneurysms (≤10 mm), 53 (26%) large aneurysms (between 10 and 25 mm), and 6 (3%) giant aneurysms (≥25 mm). Ninety-two percent of aneurysms were unruptured, and 8% were ruptured. The overall major neurologic morbidity/mortality was 4.7% and 1.8%, respectively. The all-cause mortality was 2.9%. Predictors of neurologic morbidity/mortality included the baseline modified Rankin Scale (P = 0.001), aneurysm neck size (P = 0.003), aneurysm size (P = 0.006), anterior versus posterior location (P = 0.02), and rupture at presentation (0.006). The P2Y12 Reactivity Unit, parent vessel diameter, and patient age did not correlate with adverse events. CONCLUSIONS: The PED has a satisfactory safety profile in both on- and off-label indications. A poor clinical patient baseline, wider aneurysm neck or larger size, and rupture predict an increased risk of an unfavorable outcome.