Article Text

Original research
Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms – SCENT: 3-year outcomes
  1. Ricardo A. Hanel1,
  2. Gustavo M Cortez1,
  3. Alexander L Coon2,
  4. Peter Kan3,
  5. Philipp Taussky4,
  6. Ajay K Wakhloo5,
  7. Babu G Welch6,
  8. Aclan Dogan7,
  9. Mark Bain8,
  10. Joost De Vries9,
  11. Koji Ebersole10,
  12. Philip M Meyers11
  13. SCENT Investigator Group
    1. 1 Lyerly Neurosurgery, Baptist Neurological Institute, Jacksonville, Florida, USA
    2. 2 Carondelet Neurological Institute, Carondelet Saint Joseph's Hospital, Tucson, Arizona, USA
    3. 3 Department of Neurosurgery, The University of Texas Medical Branch at Galveston School of Medicine, Galveston, Texas, USA
    4. 4 Department of Neurosurgery, University of Utah Medical Center, Salt Lake City, Utah, USA
    5. 5 Neurointerventional Radiology, Lahey Clinic Medical Center, Burlington, Massachusetts, USA
    6. 6 Neurosurgery, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
    7. 7 Interventional Neuroradiology, Oregon Health & Science University, Portland, Oregon, USA
    8. 8 Neurosurgery, Cleveland Clinic, Cleveland, Ohio, USA
    9. 9 Neurosurgery, Radboud University Nijmegen, Nijmegen, Gelderland, The Netherlands
    10. 10 Neurosurgery, Radiology, University of Kansas Medical Center Department of Neurosurgery, Kansas City, Kansas, USA
    11. 11 Radiology and Neurological Surgery, Columbia University, New York, New York, USA
    1. Correspondence to Dr Ricardo A. Hanel, Lyerly Neurosurgery, Baptist Neurological Institute, Jacksonville, Florida, USA; rhanel{at}lyerlyneuro.com

    Abstract

    Background To report the 3-year safety and effectiveness of the Surpass Streamline flow diverter in the SCENT trial (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms).

    Methods The Surpass Streamline flow diverter device was evaluated in a multicenter, prospective, single-arm, non-randomized interventional trial including patients with uncoilable or previously treated but failed aneurysms of the intracranial internal carotid artery. 3-year outcomes were tabulated with descriptive statistics and compared with 1-year outcomes.

    Results Of 180 patients in the modified intent-to-treat (mITT) cohort, 36-month clinical and angiographic follow-up was available in 134 and 117 cases, respectively. Effectiveness endpoint of complete aneurysm occlusion without clinically significant stenosis or retreatment was met in 71.8% (79/110, 95% CI 62.4% to 80.0%) of cases. Safety composite endpoint was 12.2% (22/180) over the 3-year period, with two major safety events (ipsilateral ischemic strokes) occurring between 12–36 months. Complete aneurysm occlusion was noted in 77.8% (91/117), and 99.1% (116/117) of the patients demonstrated adequate aneurysm occlusion (complete occlusion or neck residual). There were four cases (2.2%) of aneurysm rupture, all occurring within the first month of the index procedure. Target aneurysm retreatment rate was 2.8% (5/180).

    Conclusion The present findings support the long-term safety and effectiveness of the Surpass Streamline flow diverter device.

    Trial registration NCT01716117.

    • Flow Diverter
    • Aneurysm
    • Technology

    Data availability statement

    Data are available upon reasonable request.

    Statistics from Altmetric.com

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    WHAT IS ALREADY KNOWN ON THIS TOPIC

    • Flow diverters are an innovative technology for the treatment of intracranial aneurysms. The Surpass Streamline flow diverter was designed to increase the applications of flow diverter treatment. The SCENT trial 1-year outcomes support the device as a safe and effective therapy for treating large or giant aneurysms at carotid artery segments.

    WHAT THIS STUDY ADDS

    • SCENT is a prospective non-randomized interventional trial evaluating flow diverters for the treatment of intracranial aneurysms. The study outcomes were independently adjudicated, and the 3-year results are presented.

    HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

    • This study demonstrates an increasing rate of aneurysm occlusion and a low rate of new neurological events at 3-year follow-up, re-emphasizing the Surpass Streamline device as a safe strategy for managing intracranial carotid aneurysms.

    Introduction

    Rapid innovation in neurovascular device technology over the last decade has improved the effectiveness and application of flow diverters for flow remodeling of intracranial cerebral aneurysms.1 2 Yet, the treatment of large and giant aneurysms of the internal carotid artery (ICA), especially those occurring distal to the ophthalmic segment, remains a challenge with currently available stents. Left untreated, large and giant aneurysms of the ICA pose a serious risk of rupture, with some studies reporting a 5-year cumulative risk of up to 40% depending on lesion locations.3 4 The Surpass Streamline flow diverter is a second-generation braided device with improved mesh density, radial force, deliverability, and flow diversion across various device and blood vessel sizes relative to its predecessors that was designed to broaden the potential applications of flow diverter treatment.2 Early studies of the Surpass device demonstrated its safety and effectiveness for the treatment of various complex unruptured aneurysms with follow-up of up to 6 months.5 A subsequent preliminary prospective trial in Europe determined that Surpass exhibited safety comparable to that of stent-assisted coil embolization in the treatment of anterior and posterior circulation aneurysms, producing near-complete or complete aneurysm occlusion in 80% of patients at a median follow-up of 6 months and low rates of severe adverse events, especially for anterior circulation aneurysms.6

    SCENT (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms) is the first trial to formally investigate the safety and effectiveness of Surpass in a multicenter, prospective, single-arm, non-randomized, interventional design. Surpass was implanted in 180 patients with uncoilable or previously treated but failed aneurysms of the intracranial ICA from the petrous segment to the carotid terminus at its bifurcation into the anterior and middle cerebral arteries. One-year findings indicated a primary effectiveness rate of 62.8% and a 12-month adjusted major complication rate (major ipsilateral stroke or neurological death) of 11.1%, meeting both the primary and secondary performance goals as determined a priori through a meta-analysis (ie, effectiveness >50% and safety failure <20% at 1 year).7 Moreover, the availability of device lengths up to 50 mm permitted the use of a single device in most cases (on average, 1.1 per patient). The 1-year findings of the SCENT trial supported premarket approval (PMA) of Surpass by the US Food and Drug Administration (FDA) for the treatment of unruptured large or giant saccular wide-neck (neck width ≥4 mm or dome-to-neck ratio <2) or fusiform intracranial aneurysms in the ICA, from the petrous segment to the terminus arising from a parent vessel with a diameter ≥2.5 mm and ≤5.3 mm. Accordingly, Surpass is the first flow diverter approved for large and giant aneurysms in the posterior communicating artery segment.

    In ongoing fulfillment of PMA post-approval study requirements, we report 3-year follow-up findings from the SCENT trial regarding the long-term safety, effectiveness, and durability of Surpass Streamline treatment for large and giant aneurysms in the posterior communicating artery segment.

    Methods

    Patients and study design

    As previously reported,7 the SCENT trial was a multicenter, prospective, single-arm, non-randomized, interventional trial of uncoilable or previously treated but failed aneurysms of the intracranial ICA, from the petrous segment to the carotid terminus at its bifurcation into the anterior and middle cerebral arteries. Eligible patients were men and women aged 19 to 80 with large (10–24 mm) or giant (≥25 mm) wide-neck (≥4 mm) unruptured or not acutely ruptured ICA aneurysms. Patients were recruited from 26 sites in the USA and Europe from October 2012 to November 2015. Ultimately, the modified intent-to-treat (mITT) population used for safety and efficacy analyses included 180 patients with 180 aneurysms. The mITT cohort was defined as all enrolled patients in whom the Surpass Streamline flow diverter entered the body, regardless of the success of implantation.

    Protocol and registration

    Each participating center obtained Institutional Review Board approval of the investigational device exemption study protocol. Patients provided written informed consent before study participation. The trial was registered at clinicaltrials.gov (NCT01716117). A full description of the trial protocol is available on request, and details are otherwise available in the SCENT 1-year outcomes publication.7

    Device and procedure

    The Surpass Streamline flow diverter (Surpass; Stryker Neurovascular, Fremont, CA) is a second-generation device composed of cobalt-chromium alloy mesh. The number of braided wires varies between 72 and 96 depending on the chosen device diameter. Protocol required dual antiplatelet administration of oral aspirin (75–325 mg/day) and clopidogrel (75 mg/day) for at least 5 days before the procedure. Assessment of antiplatelet activity was performed with genetic testing or platelet aggregometry. All but three procedures were carried out under general anesthesia. Protocol preferably recommended placement of a single device, but a second device was allowed if judged necessary to improve proximal wall apposition and adequately cover the aneurysm neck.

    Study endpoints

    All radiological data were evaluated by an independent core radiology laboratory (CRL). Raymond-Roy occlusion classification was used to adjudicate the primary effectiveness outcome.8 The effectiveness endpoint was the rate of patients who had complete aneurysm occlusion (Raymond-Roy 1) without clinically significant in-stent stenosis (> 50%) or retreatment of the target aneurysm.

    The safety endpoint was defined as either a disabling stroke (increase in National Institutes of Health Stroke Scale (NIHSS) score ≥4) or neurological death. All serious adverse events were independently reviewed and adjudicated quarterly.

    Additional study outcomes included the incidence of aneurysm retreatment, recurrence, and rupture. Adverse events were also reported by the sites in the Electronic Data Capture system, and their potential relationship with the deployed device was raised and compared with an alternative etiology. Long-term functional outcomes were represented through the modified Rankin Scale (mRS). Additionally, the occurrence of implant migration and the degree of stenosis of the parent vessel were also evaluated.

    Follow-up assessment

    According to the study protocol, clinical follow-up occurs at 1 day, 1 month, 6 months, and yearly for up to 5 years. Angiographic follow-up was mandatory at 1 year, and additional imaging control was performed per standard of care. In the 3-year follow-up, rates are reported for patients with available clinical (safety endpoints) and/or radiological (effectiveness endpoints) follow-up at the 36-month time point.

    Statistical analyses

    Categorical data were summarized using rates and percentages. Event rates were summarized using rates and percentages. An exact binomial confidence interval was used for main study endpoints. All analyses were performed using SAS version 9.4.

    Results

    Patient and aneurysm characteristics

    Enrollment, patient demographics, and aneurysm characteristics were previously reported in the 1-year outcomes of the SCENT trial.7 Of 180 patients in the mITT cohort, seven did not complete a 12-month follow-up due to death (n=5) or study withdrawal (n=2). Between 12 and 36 months, 37 more subjects were lost to follow-up, and two additional deaths occurred. Of the 134 patients with available 3-year follow-up (safety arm), 87.3% (117/134) had follow-up angiographic imaging (effectiveness arm) at the 36-month follow-up visit. Figure 1 summarizes patient disposition over the study period. Patient demographics and aneurysm characteristics were previously reported in the 1-year outcomes of the SCENT trial.7 The location distribution of target aneurysms along the ICA is shown in table 1.

    Table 1

    Target aneurysm location mITT cohort

    Figure 1

    Flow diagram of patient enrollment and follow-up in the SCENT trial at 3-year time point. mITT, modified intent-to-treat.

    Long-term effectiveness

    Of the 110 patients with available data at the 3-year time point, 71.8% (79/110, 95% CI 62.4% to 80.0%) met the composite effectiveness endpoint of complete aneurysm occlusion without clinically significant stenosis or retreatment. Among the 31 subjects confirmed to have not met the primary efficacy endpoint, 25 were classified as Raymond 2, one was classified as Raymond 3, five had received retreatment, and one had parent artery stenosis (some of these 31 subjects failed to meet more than one of the three criteria). None of the patients with available 3-year follow-up who achieved complete occlusion underwent retreatment. Complete aneurysm occlusion progressed from 66.7% to 77.8%, and adequate aneurysm occlusion (complete occlusion and residual neck) from 83.1% to 99.1%, at 12 and 36 months, respectively. There was only one case (0.9%) of a residual aneurysm (class 3) for subjects with available data at 3-year follow-up. Effectiveness and radiological outcomes are summarized in table 2. The 1-year follow-up numbers are updated to reflect ongoing monitoring observations.

    Table 2

    Effectiveness endpoints

    Long-term safety

    Of the 134 patients with available clinical follow-up, there were two cases of ischemic stroke between 12 and 36 months. The first case was an ipsilateral posterior circulation occipital stroke that occurred 408 days after the initial procedure, and the clinical events committee (CEC) adjudicated it as unrelated to the study device or procedure. The second case occurred 958 days after the index procedure in a patient with multiple comorbidities. The patient was found to have an ipsilateral major ischemic stroke event, but the role of the flow diverter in the condition was judged uncertain. At 36 months follow-up, the cumulative major safety event rate according to CEC and following PMA review was 12.2% (22/180, 95% CI 7.8% to 17.9%). The cumulative incidence of major ipsilateral stroke or neurological death during the first year was 11.1% (20/180) and increased to 12.2% (22/180) as of the 3-year time point.

    The cumulative incidence of all-cause mortality over the 3-year follow-up was 3.9% (7/180). The five cases within the first year were adjudicated as neurological deaths. Three patients experienced subarachnoid hemorrhage during treatment, and deaths were adjudicated as procedure-related. The fourth patient was a Surpass Streamline device treatment failure who received a Pipeline device instead and died 8 days after due to a hemorrhagic stroke. The last patient had a hemorrhagic stroke associated with a methamphetamine overdose. There were two non-neurologic deaths after the 1-year follow-up. The first case was a patient with a history of subarachnoid hemorrhage and ipsilateral ischemic stroke within the first year of intervention; the patient died 898 days after the procedure due to pneumonia, septic shock, and multi-organ failure. In the second case, the patient died secondary to myocardial infarction with cardiogenic shock, status post-emergent mitral valve repair, and coronary artery bypass graft surgery. Table 3 summarizes safety and functional outcomes.

    Table 3

    Safety endpoints and functional outcomes

    Additional endpoints

    The Surpass Streamline flow diverter was successfully delivered and implanted across the aneurysm neck in 97.8% (176/180) of cases during the index procedure, with all but 21 patients (11.7%) receiving a single device. Distal migration did not occur. Cumulative incidence of retreatment at 36 months among all enrolled subjects was 2.8% (5/180). In one case retreatment occurred within 12 months of the index procedure, two cases between 12 and 24 months, and the last two cases between 24 and 36 months. Retreatment occurred at the operator’s discretion due to aneurysm residual or enlargement, and all cases were carried out with a Pipeline device. There were four (2.2%) cases of aneurysm rupture, all occurring within 1 month of the index procedure. There were no occurrences of delayed target aneurysm bleeding in the study. Among all subjects with available measurements, the rate of significant (≥50%) parent artery stenosis at 36 months was 0.9%. According to the CRL, aneurysm recurrence was noted in six cases, demonstrating residual neck filling at 3-year follow-up.

    Functional outcomes

    Most patients with available 3-year clinical follow-up had a stable (58.2%) or improved (24.6%) mRS score compared with their baseline. The rate of patients with mRS worsening was equivalent at 1- and 3-year follow-up (10%).

    Discussion

    The SCENT 3-year supports the long-term safety and efficacy of the Surpass Streamline flow diverter in the treatment of intracranial aneurysms located at the internal carotid artery. The results demonstrated increasing rates of complete aneurysm occlusion over time, progressing from 66.7% at 1-year follow-up to 77.8% at 3-year follow-up. The findings echo previous literature on flow diverters suggesting that aneurysm healing and remodeling can be expected over time. There were only two cases of major safety events in the study after 1-year follow-up and no cases of delayed aneurysm rupture, emphasizing the safety profile of the device by 3 years.

    Surpass Streamline has been investigated in a limited number of previous studies in different aneurysm contexts with primarily short-term follow-up. In an early study conducted in 2013, De Vries et al reported the treatment of 37 patients harboring 49 complex unruptured aneurysms of the ICA, middle cerebral artery (MCA), anterior cerebral artery, and posterior circulation, and reported complete occlusion in 94% of patients (plus one case of near-complete occlusion >95%) at 6-month follow-up, permanent neurological deficits in only one patient (3%), and no deaths.5 A multicenter study of 165 patients in Europe with 190 intracranial aneurysms of the anterior and posterior circulations reported complete occlusion in 75% of returning patients at a median follow-up of 6 months. Neurological death was observed in 1.6% and 7.4% of patients with aneurysms of the anterior and posterior circulation, respectively, whereas morbidity occurred in 4% and 7.5% of patients, respectively.6 More recently, Topcuoglu and colleagues investigated the combined use of Surpass and the AXS Catalyst 5 distal access catheter for the treatment of intracranial aneurysms (21 anterior circulation and four posterior circulation) with a mean follow-up of 6.3 months. Retreatment was necessary in only two cases, complete occlusion was achieved in 95% of cases, and there were no instances of permanent procedure-related morbidity or mortality.9 Surpass has been evaluated in several other studies examining multiple flow diverting stents in specific aneurysm contexts, including the cavernous sinus,10 carotid siphon,11 anterior choroidal artery,12 ‘all purpose’ treatment of MCA aneurysms (saccular and fusiform),13 and in large mixed populations13; however, these studies did not include a sufficient number of cases with Surpass devices to inform its specific safety or effectiveness relative to other devices. Finally, one single-center analysis investigated the feasibility of Surpass use in patients with acutely ruptured aneurysms. In 16 patients with 16 aneurysms, 15 achieved a favorable clinical outcome (mRS 0–1) at 3 months, one patient died of an invasive fungal infection, and angiographic follow-up showed no filling in 13 of 15 cases at 3 and 6 months.14 Together, these previous studies demonstrate the broad utility of the Surpass device, similar to the 1-year findings of the SCENT trial. The 3-year findings of SCENT support early observations and provide critical insight regarding the durability of Surpass Streamline treatment for complex unruptured intracranial ICA aneurysms. After positive results of Surpass Streamline in the SCENT trial, the second generation of the Surpass flow diverter, called Surpass Evolve, was released. The Surpass Evolve is a lower-profile implant designed to be delivered through a 0.027 inch diameter, facilitating navigation, ease of deployment, and maneuverability in tortuous intracranial anatomy, while maintaining a high-mesh density and satisfactory flow diversion profile.15

    The 3-year results showed that a significant percentage of patients with incomplete occlusion at initial follow-up progressed to complete occlusion afterward. Of the 117 patients with available 3-year angiographic follow-up, 21 cases had been adjudicated as having residual filling at 1 year. In all but one case, progression to either complete occlusion (33.3%, 7/21) or residual neck (61.9%, 13/21) was noted. These findings of progressive occlusion rates over time are supported by previous studies that elaborate on the concept of aneurysm healing and remodeling following treatment with flow diverters.16 17 Histological reorganization in the aneurysm and parent vessel results from hemodynamic flow diversion, thrombosis, and distinct cellular mechanisms occurring after deployment of the flow diverter.18 19 Current evidence supports the temporal progression to complete and durable occlusion in the long term of aneurysms treated with flow diverters. The Pipeline for Uncoilable or Failed Aneurysms (PUFS) trial investigated the use of the Pipeline embolization device to treat giant ICA aneurysms and demonstrated that complete occlusion progressed from 73.6% at 180 days to 95.2% at a 5-year follow-up.20 In a series of 116 aneurysms over a 2-year follow-up, Chiu et al revisited factors associated with delayed aneurysm occlusion following flow diverter treatment but reinforced that most of these aneurysms still occlude with time.21 In a single institutional series, Bender et al also identified progressive rates of complete aneurysm occlusion after flow diverter placement.22 In the Pipeline Embolization Devices for the Treatment of Intracranial Aneurysms (PEDESTRIAN) trial, including more than 1000 aneurysms treated with flow diversion, the rate of complete aneurysm occlusion increased from 75.8% to 96.4% after 5 years.23 Similarly, in SCENT, 91 of 117 aneurysms (77.8%) treated demonstrated complete occlusion by 3 years, with only one patient showing residual aneurysm opacification (0.9%). These findings support the long-term durability of flow diversion with devices such as Surpass Streamline.

    Major complications following flow diversion include hemorrhagic (intraparenchymal hemorrhage and postoperative aneurysm rupture) and ischemic (due to local occlusion or thromboembolic events). A growing body of evidence supports the safety profile of flow diverters at long-term follow-up and demonstrates that adverse events are more likely to occur in the initial period following the procedure. In the PUFS trial, a major safety endpoint (major stroke or neurologic death) was reported in 5.6% of cases during the first 6 months after the procedure. Subsequently, there were three serious adverse events deemed by the CEC most likely related to the device after the 180-day time point, none resulting in permanent neurological sequelae.24 A similar trend of complication timing was shown in the Aneurysm Study of Pipeline in an observational Registry (ASPIRe) study, with a 6-month major neurologic event of 6.8% but no cases of neurological morbidity and mortality after 6 months.25 Additionally, in an analysis of the International Retrospective Study of Pipeline Embolization Device (IntrePED) study involving 793 patients treated with the Pipeline embolization device, of 36 patients who had a postoperative acute ischemic stroke, 86.1% (31/36) occurred within the first 6 months of the procedure, with a smaller fraction (13.9%, 5/36) of ischemic events occurring after 6 months.26 Moreover, of the 20 cases of intraparenchymal hemorrhage reported in the study, 75% occurred within the first month of the procedure.27 Similarly, a meta-analysis performed by Cagnazzo and colleagues showed an overall higher incidence of reported periprocedural/early complications (7%, 95% CI 3% to 11%, I2=0%) compared with delayed complications (1.8%, 95% CI 1% to 5%, I2=0%).28 Based on independent adjudication at 12 months follow-up, major ipsilateral stroke or neurologic death occurred in 11.1% of patients in the SCENT trial. There were only two safety events between 1 and 3 years, corresponding to ipsilateral ischemic strokes. The temporal distribution of complications in SCENT is similar to prior reports, with a decreasing incidence of adverse events over time. Additionally, there were no cases of delayed aneurysm rupture in the SCENT trial. These findings support the safety profile of Surpass over time.

    Sidewall aneurysms commonly have a shear-driven flow due to the relative parallel location between the aneurysm ostium and parent artery. Conversely, an inertia-driven flow is perceived when the angle between the parent vessel and aneurysm ostium sharpens, generating flow instability and disruption. This difference in flow dynamics may widely interfere with the effect of flow diverter placement, as exemplified by sidewall aneurysms along ICA tortuosities, which demonstrate an inertia-driven flow attenuating the effect of flow diverters.29 30 This is particularly important when interpreting the results of the SCENT trial, as it consistently included large and giant aneurysms in the carotid communicating segment (22%) and along the curvature of the carotid siphon. Moreover, as part of the study’s design requested by the FDA, interventions were performed primarily with a single device, with only 11.7% of the patients in the SCENT trial ultimately receiving two devices. Conversely, in the PUFS trial, only a single case of a communicating carotid aneurysm (0.9%) was included, and 98% of patients received more than one device, with a median of three devices per target aneurysm (range 1–15).31 Additionally, the PUFS trial had a larger proportion of extradural aneurysms than the SCENT trial (44% vs 32%).31 These particularities are some examples that markedly distinguish these trials, impacting study outcomes and precluding head-to-head comparison between the devices.

    SCENT is a large, independently adjudicated study presenting the long-term outcomes of the Surpass Streamline flow diverter in the management of intracranial aneurysms. Surpass was used to treat a variety of aneurysms, including distal ICA aneurysms, ultimately extending its on-label use. Independent core lab adjudication demonstrated progressive rates of aneurysm occlusion, with 77.8% and 99.1% rates of complete and adequate occlusion at 3-year follow-up, respectively. The wide range of size options for the Surpass device allowed procedure optimization by permitting treatment with a single device in most cases (92%). Surpass Streamline demonstrates both safety and effectiveness at 3 years, with major ipsilateral strokes occurring in two of the 134 subjects (1.5%) between 1 and 3 years.

    Limitations

    As detailed previously, the SCENT trial was limited by a preponderance of female participants, consistent with the typical presentation of ICA aneurysms, as well as the absence of a parallel control group for comparison.7 These two limitations are common in studies of flow diverter treatment. A high rate of rupture of large and giant aneurysms precluded the inclusion of a pharmacologically managed control group, whereas other surgical options such as parent vessel occlusion or aneurysm clipping are associated with high rates of morbidity and mortality and would not have been an ethical selection for control treatment, given expectations of safety derived from previous investigations of Surpass Streamline implementation.

    Conclusion

    SCENT is a prospective, independently adjudicated trial to assess the long-term safety, effectiveness, and durability of treating intracranial aneurysms using the Surpass Streamline device. This study demonstrates an increasing rate of aneurysm occlusion and low rate of new neurological events at 3-year follow-up.

    Supplemental material

    Data availability statement

    Data are available upon reasonable request.

    Ethics statements

    Patient consent for publication

    Ethics approval

    This study involves human participants and was approved by Mayo Rochester – Mayo Clinic Institutional Review Boards: 12-006476 Mayo Florida – Mayo Clinic Institutional Review Boards: 12-006477OHSU – Research Integrity Office OHSU: IRB00008853 Columbia University – Institutional Review Board CU IRB: IRB-AAAK7205 University of Florida – WIRB: 1135134 Rush University Medical C – Rush University Medical Center: 12103001-IRB01 Baptist Health South Florida – Baptist Health South Florida: IRB2012-101Johns Hopkins Medicine – Office of Human Subjects Research Board: NA_00082896 Thomas Jefferson – Office of Human Research: 13C.03UT Southwestern Medical Center – University of Texas Southwestern Medical Center Institutional Review Board: STU 112012-010 University of Utah – Institutional Review Board University of Utah: 00063670 Vanderbilt University – Vanderbilt University Institutional Review Board: 121894UMC St Radboud Netherlands – EC UMC St Radboud: NL41777.091.12 Cleveland Clinic – Cleveland Clinic Institutional Review Board: 14-100MUSC – Office of Research Integrity Medical University of South Carolina: Pro00029252 Tampa General – WIRB: 20121614 Froedtert Hospital – Medical College of Wisconsin/Froedtert Hospital Institutional Review Board: PRO00020850 University of Virginia – University of Virginia Institutional Review Board for Health Sciences Research: 17130 Fort Sanders – Covenant Health IRB: 2014-183 Lyerly – Baptist Medical Center IRB: 14-19 University of Massachusetts – University of Massachusetts Medical School IRB: H00003919 Buffalo – SUNY University at Buffalo Health Sciences IRB: 533715-2KUMC – University of Kansas Medical Center Human Research Protection Program: 00002010 Baylor – BRANY: 15-02-10-181 UCI – UC Irvine Office of Research: 2015-1841 Santa Barbara – Santa Barbara Cottage Health System: 15-17. Participants gave informed consent to participate in the study before taking part.

    Acknowledgments

    The authors acknowledge Patricia Morgan and Stryker team for their assistance.

    References

    Supplementary materials

    • Supplementary Data

      This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.

    Footnotes

    • RAH and GMC are joint first authors.

    • Twitter @dralexandercoon, @PeterKa80460001

    • Collaborators SCENT Investigator Group (sorted by number of patients recruited):John Hopkins University (25) – A Coon (Past PI), G Colby (Past PI), Justin Caplan (Current PI) (did not treat patients but is current PI); Li-Mei Lin (Sub-I)Tampa General Hospital (16) - P Kan (PI), M Mokin (PI) (did not treat patients but is current PI); Zinovy Katz (Sub-I) Oregon Health and Science University (14) - A Dogan (PI and Past Sub-I), S Barnwell (Past PI), R Priest (Past PI and Current Sub-I), H Bozorgchami (Sub-I), W Clark (Sub-I); B Petersen (Sub-I); G Nesbit (Sub-I); H Lutsep (Sub-I); S Ford (Sub-I); Noah Beadell (Sub-I); Jeremy Fields (Sub-I); Kory Herrick (Sub-I); David Hoak (Sub-I); Scott Rewinkel (Sub-I); Andrew Rontal (Sub-I); Stewart Weber (Sub-I); University of Texas – Southwestern (11) - B Welch (PI), GL Pride (Sub-I); Kim Dutton-Johnson (Sub-I); Nikhil Mehta (PI); Cleveland Clinic (11) - M Bain (PI), G Toth (Sub-I) UMC St Radboud (The Netherlands) (10) – J DeVries (PI), H Boogaarts (Sub-I); University of Kansas Medical Center (10) - K Ebersole (PI), A Reeves (Sub-I), EJ Madarang (Sub-I) Rush University Medical Center (8) - DK Lopes (Past PI), R Moftakhar (Sub-I); M Chen (Current PI and Past Sub-I); Richard Crowley (Sub-I); R Moftakhar (Sub-I); University of Massachusetts Medical School (8) - A Puri (PI), F Massari (Sub-I); (7) - G Lanzino (PI), H Cloft (Sub-I); D Kallmes (Sub-I); Columbia University (7) - P Meyers (PI), S Lavine (Sub-I); G Mandigo (Sub-I); Daniel Sahlein (Past Sub-I); University of Florida – Gainesville (6) - B Hoh (Past PI and Current Sub-I), Spiros Blackburn, MD (Past PI), C Fox (Current PI did not treat patients but is the current PI); Thomas Jefferson University (6) - P Jabbour (PI), S Tjoumakaris (Sub-I); R Rosenwasser (Sub-I); Aaron Dumont (Sub-I); Fernando Gonzalez (Sub-I); Fort Sanders Regional Medical Center (6) - K Woodward (PI); University of California – Irvine (6) - LM Lin (PI), S Suzuki (Sub-I); K Golshani (Sub-I); Mayo Clinic – Florida (5) – R Hanel (past PI), R Tawk (PI and Past Sub-I); D Miller (Sub-I); Vanderbilt University Medical Center (4) – J Mocco (past PI), M Froehler (PI did not treat patients but is current PI), Lyerly Neurosurgery (4) - R Hanel (PI), E Sauvageau (Sub-I); Baylor College of Medicine (4) - P Kan (PI); Edward Duckworth (Sub-I); Hesham Morsi (Sub-I); University of Utah (3) - P Taussky (PI), E Stevens (Sub-I); Min Paru (Sub-I); University of Virginia (3) - A Evans (PI did not treat patients), K Liu (past PI) (Sub-I); R Crowley (Sub-I); P Schweickert (Sub-I); L Fulks (Sub-I); A Walton (Sub-I); H Hixon (Sub-I); JM Gingras (Sub-I); P Schmitt (Sub-I); D Raper (Sub-I); Christopher Durst (Sub-I); Robert Starke (Sub-I); Santa Barbara Cottage Hospital (2) - A Zauner (PI), R Taylor(Sub-I); Samuel Hou (Sub-I); Baptist Hospital of Miami (1) - G Dabus (PI); I Linfante (Sub-I); Medical University of South Carolina (1) - R Turner (Current PI Resigning Nov 30), M Chaudry(Sub-I); A Turk (Sub-I); A Spiotta (Current Sub-I. PI beginning Nov 30. Waiting on IRB Approval from Site) Medical College of Wisconsin Froedtert Hospital (1) – O Zaidat (Past PI), BF Fitzsimmons (Current PI Past Sub-I did not treat patients but is current PI), J Lynch (Sub-I); M Lazzaro (Sub-I); University of Buffalo (1) – A Siddiqui (PI), K Snyder (Sub-I); E Levy (Sub-I).

    • Contributors RAH and GMC drafted the initial manuscript and are joint first authors. All authors were involved and made substantial contributions to the conception or design of the work, or the acquisition, analysis, or interpretation of the data; revising it critically for important intellectual content; final approval of the version published; and agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. RAH is responsible for the overall content as the guarantor.

    • Funding This study was sponsored by Stryker. The sponsor of the study was responsible for site management, data management and monitoring, safety reporting, and statistical analysis. An academic steering committee supervised trial design and operations. A publication committee comprised of the academic steering committee and academic principal investigators who enrolled most patients interpreted the results and wrote the report. The corresponding author had full access to all the data and had final responsibility for the decision to submit for publication. SCENT (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms) is registered with ClinicalTrials.gov (URL: https://www.clinicaltrials.gov Unique identifier: NCT01716117).

    • Competing interests RAH is a consultant for Stryker, Medtronic, Cerenovous, Microvention, Balt, Phenox, Rapid Medical, and Q’Apel. He is on the advisory board for MiVI, eLum, Three Rivers, Shape Medical, and Corindus. Unrestricted research grant from NIH, Interline Endowment, Microvention, Stryker, CNX. Investor/stockholder for InNeuroCo, Cerebrotech, eLum, Endostream, Three Rivers Medical Inc, Scientia, RIST, BlinkTBI, and Corindus. GMC has no disclosures to report. ALC serves as a consultant for Stryker, Medtronic, Microvention, InNeuroCo, Rapid Medical, Q’Apel, Imperative Care, and AVAIL Medsystems. PTK serves as a consultant for Stryker, Imperative Care, Cerenovus, and Microvention; research grant from NIH, Siemens, Joe Niekro, and Medtronic; Journal of NeuroInterventional Surgery editorial board. PT serves as a consultant for Stryker, Cerenovus, and Medtronic. AKW has research grants from Philips Medical, fellowship grant from Medtronic; serves as a consultant for Stryker, Phenox, and Cerenovus JNJ; is a stockholder of InNeuroCo, EpiEP, Neural Analytics, RISt, Analytics 4 Life, and ThrombX; and is on the Speakers’ Bureau for SCENT trial (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms) presentations. BGW served as a consultant/proctor for Stryker and is the past Chair of AANS/CNS Cerebrovascular section. AD has no disclosures to report. MDB serves as a consultant for Stryker and was on the hemorrhagic advisory board for Stryker. JDV serves as a consultant for Stryker Neurovascular and Evasc Ltd and was part of the screening committee French EESIS study (Evasc). KE serves as a consultant for Stryker and Microvention and was a member of the Cerebrovascular Section Joint Guidelines Review Committee. PMM serves as a consultant for Stryker, Medtronic, and Penumbra.

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.