Showing papers in "Journal of NeuroInterventional Surgery in 2017"

A population-based incidence of acute large vessel occlusions and thrombectomy eligible patients indicates significant potential for growth of endovascular stroke therapy in the USA.

Abstract: Background Data on large vessel strokes are important for resource allocation and infrastructure development. Objective To determine an annual incidence of large vessel occlusions (LVOs) and a thrombectomy eligible patient population. Methods All patients with acute ischemic stroke discharged over 3 years from a tertiary-level hospital serving a large geographic area were evaluated for an LVO (M1, internal carotid artery terminus, basilar artery). The incidence of LVO was determined for the hospital9s 4-county primary service area (PSA, population 210 000) based on each county9s discharges and extrapolated to the US population. ‘Thrombectomy eligibility’ for anterior circulation LVOs was based on time (onset Results 1157 patients were discharged from the hospital9s PSA, of whom 129 (11.1%, 95% CI 9.5% to 13.1%) had an LVO. This translated into an LVO incidence of 24 per 100 000 people per year (95% CI 20 to 28). 20 per 100 000 people per year had anterior circulation LVOs (95% CI 19 to 22), of whom 10/100 000/year (95% CI 8 to 11) were ‘thrombectomy eligible’. An additional 5/100 000/year (95% CI 3 to 6) presented with favorable ASPECTS after 6 hours of symptom onset. Basilar occlusion incidence was estimated at 4/100 000/year (95% CI 2 to 5). These rates yield 77 569 (95% CI 65 835 to 91 091) new LVOs per year in the USA. An estimated 10 284 mechanical thrombectomy procedures were performed in 2015. Conclusions This study estimates an LVO incidence of 24 per 100 000 person-years (95% CI 20 to 28). A current estimated annual thrombectomy rate of three procedures per 100 000 people indicates significant potential increase in the volume of endovascular procedures and the need to develop systems of care.

Correlation of imaging and histopathology of thrombi in acute ischemic stroke with etiology and outcome: a systematic review

Abstract: Background and purpose Studying the imaging and histopathologic characteristics of thrombi in ischemic stroke could provide insights into stroke etiology and ideal treatment strategies We conducted a systematic review of imaging and histologic characteristics of thrombi in acute ischemic stroke Materials and methods We identified all studies published between January 2005 and December 2015 that reported findings related to histologic and/or imaging characteristics of thrombi in acute ischemic stroke secondary to large vessel occlusion The five outcomes examined in this study were (1) association between histologic composition of thrombi and stroke etiology; (2) association between histologic composition of thrombi and angiographic outcomes; (3) association between thrombi imaging and histologic characteristics; (4) association between thrombi imaging characteristics and angiographic outcomes; and (5) association between imaging characteristics of thrombi and stroke etiology A meta-Analysis was performed using a random effects model Results There was no significant difference in the proportion of red blood cell (RBC)-rich thrombi between cardioembolic and large artery atherosclerosis etiologies (OR 162, 95% CI 01 to 280, p=063) Patients with a hyperdense artery sign had a higher odds of having RBC-rich thrombi than those without a hyperdense artery sign (OR 90, 95% CI 26 to 312, p<001) Patients with a good angiographic outcome had a mean thrombus Hounsfield unit (HU) of 551±31 compared with a mean HU of 484±19 for patients with a poor angiographic outcome (mean standard difference 65, 95% CI 27 to 102, p<0001) There was no association between imaging characteristics and stroke etiology (OR 113, 95% CI 032 to 400, p=085) Conclusions The hyperdense artery sign is associated with RBC-rich thrombi and improved recanalization rates However, there was no association between the histopathological characteristics of thrombi and stroke etiology and angiographic outcomes

Continuous aspiration prior to intracranial vascular embolectomy (CAPTIVE): a technique which improves outcomes.

Abstract: Background Modern stent retriever-based embolectomy for patients with emergent large vessel occlusion improves outcomes. Techniques aimed at achieving higher rates of complete recanalization would benefit patients. Objective To evaluate the clinical impact of an embolectomy technique focused on continuous aspiration prior to intracranial vascular embolectomy (CAPTIVE). Methods A retrospective review was performed of 95 consecutive patients with intracranial internal carotid artery or M1 segment middle cerebral artery occlusion treated with stent retriever-based thrombectomy over an 11-month period. Patients were divided into a conventional local aspiration group (traditional group) and those treated with a novel continuous aspiration technique (CAPTIVE group). We compared both early neurologic recovery (based on changes in National Institute of Health Stroke Scale (NIHSS) score), independence at 90 days (modified Rankin score 0–2), and angiographic results using the modified Thrombolysis in Cerebral Ischemia (TICI) scale including the TICI 2c category. Results There were 56 patients in the traditional group and 39 in the CAPTIVE group. Median age and admission NIHSS scores were 78 years and 19 in the traditional group and 77 years and 19 in the CAPTIVE group. Median times from groin puncture to recanalization in the traditional and CAPTIVE groups were 31 min and 14 min, respectively (p Conclusions The CAPTIVE embolectomy technique may result in higher recanalization rates and better clinical outcomes.

Time to redefine success? TICI 3 versus TICI 2b recanalization in middle cerebral artery occlusion treated with thrombectomy

Abstract: Background The Thrombolysis in Cerebral Infarction (TICI) scale is the most widely applied scoring system to grade technical results of recanalizing therapies in acute ischemic stroke (AIS). TICI 2b and TICI 3 are conventionally subsumed as ‘successful recanalization’. Previous studies reported conflicting results for the clinical relevance of achieving complete (TICI 3) versus ‘almost’ complete reperfusion (TICI 2b). Objective To examine if neurologic outcome differs significantly between TICI 2b and TICI 3 in patients with AIS with middle cerebral artery (MCA) occlusion treated ‘successfully’ with mechanical thrombectomy (MTE). Methods Retrospective analysis of prospectively collected data from 352 consecutive patients with isolated MCA occlusion subjected to MTE between January 2007 and July 2015. Results 262 of the 277 successfully treated patients had adequate follow-up and were included. Patients (n=119) in the TICI 3 group had a lower National Institutes of Health Stroke Scale score at discharge (NIHSS-DIS; median 5 vs 7, p=0.005), and showed higher rates of strong neurologic improvement (ΔNIHSS≥8 or NIHSS-DIS≤1, 68.4% vs 37.1%, p=0.002) and favorable NIHSS outcome (NIHSS-DIS≤5, 49.2% vs 31.9%, p=0.005). Hospital stays were shorter in the TICI 3 group (median 10 vs 12 days, p=0.014). After adjusting for relevant baseline and treatment parameters, TICI 3 was independently associated with strong neurologic improvement (OR=4.3, 95% CI 2.2 to 8.3, p Conclusions Neurologic outcome is substantially better in TICI 3 than TICI 2b patients, and hospital stays are shorter. Endovascular strategies that consequently strive to achieve TICI 3 may be warranted and cost-effective, and should be examined by future research. TICI 3 rates should be included as a safety measure in studies evaluating MTE devices and techniques.

Initial hospital management of patients with emergent large vessel occlusion (ELVO): report of the standards and guidelines committee of the Society of NeuroInterventional Surgery

Abstract: Objective To summarize the current literature regarding the initial hospital management of patients with acute ischemic stroke (AIS) secondary to emergent large vessel occlusion (ELVO), and to offer recommendations designed to decrease the time to endovascular treatment (EVT) for appropriately selected patients with stroke. Methods Using guidelines for evidenced-based medicine proposed by the Stroke Council of the American Heart Association, a critical review of all available medical literature supporting best initial medical management of patients with AIS secondary to ELVO was performed. The purpose was to identify processes of care that most expeditiously determine the eligibility of a patient with an acute stroke for interventions including intravenous fibrinolysis with recombinant tissue plasminogen activator (IV tPA) and EVT using mechanical embolectomy. Results This review identifies four elements that are required to achieve timely revascularization in ELVO. (1) In addition to non-contrast CT (NCCT) brain scan, CT angiography should be performed in all patients who meet an institutional threshold for clinical stroke severity. The use of any advanced imaging beyond NCCT should not delay the administration of IV tPA in eligible patients. (2) Activation of the neurointerventional team should occur as soon as possible, based on either confirmation of large vessel occlusion or a prespecified clinical severity threshold. (3) Additional imaging techniques, particularly those intended to physiologically select patients for EVT (CT perfusion and diffusion–perfusion mismatch imaging), may provide additional value, but should not delay EVT. (4) Routine use of general anesthesia during EVT procedures, should be avoided if possible. These workflow recommendations apply to both primary and comprehensive stroke centers and should be tailored to meet the needs of individual institutions. Conclusions Patients with ELVO are at risk for severe neurologic morbidity and mortality. To achieve the best possible clinical outcomes stroke centers must optimize their triage strategies. Strategies that provide patients with ELVO with the fastest access to reperfusion depend upon detail-oriented process improvement.

Endovascular mechanical thrombectomy for cerebral venous sinus thrombosis: a systematic review

Abstract: Background Cerebral venous sinus thrombosis (CVST) is an uncommon form of stroke that, when severe, can be a therapeutic challenge. Endovascular mechanical thrombectomy (EMT) techniques have significantly evolved over the past decade, but data regarding the efficacy and safety of EMT for CVST are poorly defined. Objective To summarize the large number of case series on this relatively rare condition and establish trends in the outcomes of EMT for CVST. Methods A literature review was performed using PubMed and Medline to identify reports of three or more patients with CVST treated with EMT. Baseline and outcomes data, including radiographic resolution, neurological outcome, recurrence, and treatment-related complications, were extracted for analysis. Results A total of 17 studies comprising 235 patients treated with EMT were included for analysis. Based on pooled data, 40.2% of patients presented with encephalopathy or coma. Concurrent endovascular thrombolysis was employed in 87.6% of patients. Complete radiographic resolution of CVST was achieved in 69.0% of patients. At follow-up (range 0.5–3.5 years), 34.7% of patients were neurologically intact and the mortality rate was 14.3%. CVST recurrence was evident in 1.2%. Worsening or new intracranial hemorrhage (ICH) occurred in 8.7% of cases. ORs of good outcome (modified Rankin Scale score 0–2) and development of ICH with sole EMT versus concurrent thrombolytic therapy were 1.51 (95% CI 0.29 to 8.15, p=0.61) and 1.15 (95% CI 0.12 to 10.80, p=0.90), respectively. Conclusions EMT is an effective salvage therapy for refractory CVST, with a reasonable safety profile. Chemical thrombolysis, in conjunction with EMT, did not appear to result in additional harm or benefit. Further analysis is warranted to determine predictors of success after EMT for CVST.

Admission CT perfusion may overestimate initial infarct core: the ghost infarct core concept

Abstract: Background Identifying infarct core on admission is essential to establish the amount of salvageable tissue and indicate reperfusion therapies. Infarct core is established on CT perfusion (CTP) as the severely hypoperfused area, however the correlation between hypoperfusion and infarct core may be time-dependent as it is not a direct indicator of tissue damage. This study aims to characterize those cases in which the admission core lesion on CTP does not reflect an infarct on follow-up imaging. Methods We studied patients with cerebral large vessel occlusion who underwent CTP on admission but received endovascular thrombectomy based on a non-contrast CT Alberta Stroke Program Early CT Score (ASPECTS) >6. Admission infarct core was measured on initial cerebral blood volume (CBV) CTP and final infarct on follow-up CT. We defined ghost infarct core (GIC) as initial core minus final infarct >10 mL. Results 79 patients were studied. Median National Institutes of Health Stroke Scale (NIHSS) score was 17 (11–20), median time from symptoms to CTP was 215 (87–327) min, and recanalization rate (TICI 2b–3) was 77%. Thirty patients (38%) presented with a GIC >10 mL. GIC >10 mL was associated with recanalization (TICI 2b–3: 90% vs 68%; p=0.026), admission glycemia ( 185 min: 26%; p=0.033). An adjusted logistic regression model identified time from symptom to CTP imaging 10 mL (OR 2.89, 95% CI 1.04 to 8.09). At 24 hours, clinical improvement was more frequent in patients with GIC >10 mL (66.6% vs 39%; p=0.017). Conclusions CT perfusion may overestimate final infarct core, especially in the early time window. Selecting patients for reperfusion therapies based on the CTP mismatch concept may deny treatment to patients who might still benefit from reperfusion.

Demographic, procedural and 30-day safety results from the WEB Intra-saccular Therapy Study (WEB-IT)

Abstract: Introduction The Woven EndoBridge (WEB) represents a novel intrasaccular therapeutic option for the treatment of intracranial wide-necked bifurcation aneurysms (WNBAs). The WEB-IT Study is a pivotal Investigational Device Exemption (IDE) study to determine the safety and effectiveness of the WEB device for the treatment of WNBAs located in the anterior and posterior intracranial circulations. We present the patient demographics, procedural characteristics, and 30-day adverse event data for the US WEB-IT study. Methods WEB-IT is a prospective multicenter single-arm interventional study conducted at 25 US and 6 international centers. The study enrolled 150 adults with WNBAs of the anterior and posterior intracranial circulations. All patients were intended to receive a WEB device delivered via standard endovascular neurosurgical embolization techniques. The study was conducted under Good Clinical Practices and included independent adjudication effectiveness outcomes and all adverse events. Results One hundred and fifty patients enrolled at 27 investigational sites underwent attempted treatment with the WEB. Mean age was 59 years (range 29–79) and 110 (73.3%) of the patients were female. Treated aneurysms were located at the basilar apex (n=59, 39.3%), middle cerebral artery bifurcation (n=45, 30%), anterior communicating artery (n=40, 26.7%), and internal carotid artery terminus (n=6, 4%). Average aneurysm size was 6.4 mm (range 3.6–11.4) with a mean neck size of 4.8 mm (range 2.0–8.2, mean dome to neck ratio 1.34). Nine patients presented with ruptured aneurysms. Of the enrolled patients, 98.7% were treated successfully with WEB devices. Mean±SD fluoroscopy time was 30.2±15.7 min. One primary safety event (PSE) (0.7%)—a delayed parenchymal hemorrhage 22 days after treatment—occurred between the index procedure and 30-day follow-up. In addition to the single PSE, there were seven (4.7%) minor ischemic strokes (5 resolved without sequelae and 2 had a modified Rankin Scale score of 1 at 30 days), five (2.7%) transient ischemic attacks, and two (1.3%) minor subarachnoid hemorrhages, which did not meet the prospectively established criteria for PSEs. Conclusions The WEB device can be used to treat WNBAs with a high level of procedural safety and a high degree of technical success. Trial registration number NCT02191618; Pre-results.

Stroke vision, aphasia, neglect (VAN) assessment-a novel emergent large vessel occlusion screening tool: pilot study and comparison with current clinical severity indices.

Abstract: Background Identification of emergent large vessel occlusion (ELVO) stroke has become increasingly important with the recent publications of favorable acute stroke thrombectomy trials. Multiple screening tools exist but the length of the examination and the false positive rate range from good to adequate. A screening tool was designed and tested in the emergency department using nurse responders without a scoring system. Methods The vision, aphasia, and neglect (VAN) screening tool was designed to quickly assess functional neurovascular anatomy. While objective, there is no need to calculate or score with VAN. After training participating nurses to use it, VAN was used as an ELVO screen for all stroke patients on arrival to our emergency room before physician evaluation and CT scan. Results There were 62 consecutive code stroke activations during the pilot study. 19 (31%) of the patients were VAN positive and 24 (39%) had a National Institutes of Health Stroke Scale (NIHSS) score of ≥6. All 14 patients with ELVO were either VAN positive or assigned a NIHSS score ≥6. While both clinical severity thresholds had 100% sensitivity, VAN was more specific (90% vs 74% for NIHSS ≥6). Similarly, while VAN and NIHSS ≥6 had 100% negative predictive value, VAN had a 74% positive predictive value while NIHSS ≥6 had only a 58% positive predictive value. Conclusions The VAN screening tool accurately identified ELVO patients and outperformed a NIHSS ≥6 severity threshold and may best allow clinical teams to expedite care and mobilize resources for ELVO patients. A larger study to both validate this screening tool and compare with others is warranted.

Experimental evaluation of stent retrievers' mechanical properties and effectiveness.

Abstract: Background Five randomized controlled trials recently appeared in the literature demonstrating that early mechanical thrombectomy in patients with acute ischemic stroke is significantly related to an improved outcome. Stent retrievers are accepted as the most effective devices for intracranial thrombectomy. Objective To analyze the mechanical properties of stent retrievers, their behavior during retrieval, and interaction with different clots and to identify device features that might correlate with the effectiveness of thrombus removal. Materials and methods All stent retrievers available in France up to June 2015 were evaluated by mechanical and functional tests aimed at investigating the variation of their radial force and their behavior during retrieval. Devices were also tested during in vitro thrombectomies using white and red experimental thrombi produced with human blood. Functional tests and in vitro thrombectomies were conducted using a rigid 3D printed vascular model. Results Mechanical tests showed a variation in radial force during retrieval for each stent. A constant radial force during retrieval was related to continuous cohesion over the vessel wall and a higher rate of clot removal efficacy. All stent retrievers failed when interacting with white large thrombi (diameter ≥6 mm). Conclusions None of the tested devices were effective in removing white clots of large diameter (≥6 mm). Constant radial force during retrieval allows constant cohesion to the vessel wall and pressure over the clot; such features allow for a higher rate of clot removal.

Too good to intervene? Thrombectomy for large vessel occlusion strokes with minimal symptoms: an intention-to-treat analysis

Abstract: Introduction The minimal stroke severity justifying endovascular intervention remains elusive; however, a significant proportion of patients presenting with large vessel occlusion (LVO) and mild symptoms subsequently decline and face poor outcomes. Objective To evaluate our experience with these patients by comparing best medical therapy with thrombectomy in an intention-to-treat analysis. Methods Analysis of prospectively collected data of all consecutive patients with National Institutes of Health Stroke Scale (NIHSS) score ≤5, LVO on CT angiography, and baseline modified Rankin Scale (mRS) score 0–2 from November 2014 to May 2016. After careful discussion with patients/family, a decision to pursue medical or interventional therapy was made. Deterioration (development of aphasia, neglect, and/or significant weakness) triggered reconsideration of thrombectomy. The primary outcome measure was NIHSS shift (discharge NIHSS score minus admission NIHSS score). Results Of the 32 patients qualifying for the study, 22 (69%) were primarily treated with medical therapy and 10 (31%) intervention. Baseline characteristics were comparable. Nine (41%) medically treated patients had subsequent deterioration requiring thrombectomy. Median time from arrival to deterioration was 5.2 hours (2.0–25.0). Successful reperfusion (modified Treatment in Cerebral Infarction 2b−3) was achieved in all 19 thrombectomy patients. The NIHSS shift significantly favored thrombectomy (−2.5 vs 0; p Conclusions Thrombectomy led to a shift towards a lower NIHSS in patients with LVO presenting with minimal stroke symptoms. Despite the overall perception that this condition is benign, nearly a quarter of patients primarily treated with medical therapy did not achieve independence at 90 days.

Comparison of outcome and interventional complication rate in patients with acute stroke treated with mechanical thrombectomy with and without bridging thrombolysis.

Abstract: Background No randomized trial has investigated the effect of mechanical thrombectomy (MT) alone in patients with acute stroke. There are conflicting results as to whether prior intravenous thrombolysis (IVT) facilitates subsequent MT, and data in patients treated with MT alone owing to contraindications to IVT are limited. Objective To compare consecutive patients treated with MT alone or with preceding IVT in a large tertiary neurointerventional center, with special emphasis on contraindications to IVT. Methods Retrospective analysis of 283 consecutive patients with acute ischemic stroke treated with MT in a tertiary neurovascular center over 14 months. Data on characteristics of periprocedural times, recanalization rate, complications, and long-term functional outcome were collected prospectively. Results Information on prior IVT and functional outcome was available in 250 patients. Mean (SD) follow-up period was 5.7 (5.1) months and 105 (42%) patients received both IVT and MT. No significant differences were found in successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) 2b/3, 73.8% vs 73.1, p=0.952), complication rates, and long-term favorable outcome (modified Rankin Scale 0–2, 35.2% vs 40%, p=0.444) between patients receiving MT plus IVT and those receiving MT alone. A favorable outcome in patients directly treated with MT alone who were eligible for IVT was achieved in 48.2%. Thrombectomy was safe and resulted in a favorable outcome in 32% of patients with absolute contraindications to IVT. Conclusions Preceding use of IVT was not an independent predictor of favorable outcome in patients with acute stroke treated with MT and complication rates did not differ whether or not IVT was used. MT is safe and achieved a favorable outcome in one-third of patients with stroke ineligible for IVT.

Treatment of posterior circulation non-saccular aneurysms with flow diverters: a single-center experience and review of 56 patients

Abstract: Background and purpose Non-saccular aneurysms of the posterior fossa are an uncommon pathology with no clear treatment strategy. The use of flow-diverting stents (FDS) has had mixed results. We sought to evaluate our experience of FDS for the treatment of this pathology. Methods We retrospectively reviewed our database of prospectively collected information for all patients treated only with flow diversion for an unruptured non-saccular aneurysm of the posterior circulation between February 2009 and April 2016. The aneurysms were classified as dolichoectasia, fusiform or transitional, and imaging characteristics including maximal diameter, disease vessel segment, MRI features (intra-aneurysmal thrombus, T1 hyperintensity in the aneurysmal wall, infarctions in the territory of the posterior circulation, and mass effect) were recorded alongside clinical and follow-up data. Results We identified 56 patients (45 men) with 58 aneurysms. The average age of the patients was 63.5 years. Twenty-two patients were symptomatic from the aneurysms at presentation. The majority of the lesions were vertebrobasilar in location (44.8%) with isolated vertebral lesions representing 29.3% of aneurysms. Transitional aneurysms were the most common (48.2%). The mean maximal diameter of the aneurysms was 11 mm. Angiographic exclusion of the aneurysms was seen in 57.4% of aneurysms with follow-up (n=47). During the follow-up period nine patients died. Conclusions Treatment of non-saccular aneurysms of the posterior fossa is technically possible. Early treatment, particularly of the fusiform and transitional subtypes, is recognized, as is treatment prior to the development of symptoms. A ‘watch and wait’ strategy with regular imaging follow-up could be employed for asymptomatic dolichoectasia.

A comparison of acute vascular damage caused by ADAPT versus a stent retriever device after thrombectomy in acute ischemic stroke: a histological and ultrastructural study in an animal model

Abstract: Background It has been amply demonstrated that endovascular procedures can be successful treatment for stroke, both in terms of revascularization and clinical outcome. There is not, however, a published comparison of any histological or ultrastructural damage to the vessels that may be caused by a direct aspiration first pass technique (ADAPT) or stent retrievers (SR) used in these procedures. This study analyses and compares acute damage to the arterial wall caused by ADAPT or SR. Material and methods Damage to the walls of swine extracranial arteries was evaluated after ADAPT with the Penumbra system or thrombectomy with an SR (Solitaire 6×30). The procedures were performed after injecting thrombi into the selected arteries (arteries with diameters similar to those of the human internal carotid artery and first segment of the middle cerebral artery). After the procedures, the animal was euthanized and 12 arterial samples were obtained for analysis by optical and electronic microscopy. Results Tissue samples from the vessels treated with SR showed almost complete loss of endothelium, thickening of the internal elastic lamina, and degeneration of the elastic fibers of the bordering lamina media and adventitia. In contrast, tissue samples of the vessels treated with ADAPT had a clear integral internal elastic lamina and uninterrupted endothelial lining, although cell alignment was altered and there were surface lacerations due to manipulation of the samples. Conclusions Both techniques caused acute damage to the vessel walls, however, thrombectomy with SR appeared to be more harmful to all layers of the arterial wall, particularly the endothelium.

Novel methodology to replicate clot analogs with diverse composition in acute ischemic stroke

Abstract: Background Translational research on clot composition may be advanced by the use of clot analogs for the preclinical evaluation of mechanical thrombectomy devices. This work describes a novel set of clot analogs to represent a diverse range of fibrin and red blood cell (RBC) compositions for use in acute ischemic stroke (AIS) occlusion models. Method Fresh whole blood obtained from ovine species was used to create seven different clot analog types. Five replicates were formed for each clot type. Varying amounts of whole blood constituents were mixed with thrombotic factors to create clots of varying compositions. Following histological processing, five sections from each clot were stained with H&E and Martius Scarlet Blue. Fibrin, RBC and white blood cell compositions were quantified. Results Histological examination demonstrated that the clot types had a distinct RBC and fibrin composition. No significant difference in composition was shown between replicates (p>0.05), indicating that the method of clot formation was reproducible. Percentage fibrin composition of the clot types was 1%, 8%, 31%, 38%, 64%, 79%, and 100%. A significant difference in fibrin and RBC composition between clot types was observed (p Conclusions Seven different clot types were developed to replicate common AIS thrombi. These clot analogs may be beneficial for the preclinical evaluation of endovascular therapies, and may be applied to interventional technique training.

Flow diversion with Pipeline Embolic Device as treatment of subarachnoid hemorrhage secondary to blister aneurysms: dual-center experience and review of the literature

Abstract: Background Aneurysmal subarachnoid hemorrhage (aSAH) secondary to blister-type aneurysms (BAs) is associated with high morbidity and mortality. Microsurgical clipping or wrapping and/or use of traditional endovascular techniques to repair the lesion result in frequent regrowth and rebleeds and ultimately high fatality rates. Because of the purely endoluminal nature of arterial reconstruction, flow diversion may represent an ideal option to repair ruptured BAs. Methods We performed a retrospective analysis of our database including all consecutive patients with aSAH secondary to BAs treated with the Pipeline Embolic Device (PED) between November 2013 and November 2015 in two institutions. We collected basic patient demographics, aneurysm size, location, number and sizes of PEDs used, use of coiling, 30-day modified Rankin Scale (mRS) score, and follow-up imaging data. Results Ten cases of aSAH were found as a result of a ruptured BA. Patients had a mean age of 47.2 years (range 27–68). Mean Hunt and Hess score was 1.6 (range 1–4). Lesions were predominantly left-sided, mostly along the dorsal aspect of the internal carotid artery, either paraclinoid or paraophthalmic (8/10). In two patients the BA was located in the left middle cerebral artery. All lesions were very small (mean 1.4×1.5 mm; range 0.75–2.1 mm). Placement of a single PED resulted in immediate occlusion or near-occlusion of the BA in 9 out of 10 patients. Nine patients did very well; eight had a 90-day mRS score of 0 and one had a 90-day mRS score of 1. Follow-up digital subtraction angiography was performed in all patients (mean 15 months; range 7–24). In the surviving nine patients there was complete occlusion of the BA on long-term follow-up angiography. Conclusions Repair of ruptured BA with PED may be a safe and durable option.

Vessel perforation during stent retriever thrombectomy for acute ischemic stroke: technical details and clinical outcomes

Abstract: Background Vessel perforation during stent retriever thrombectomy is a rare complication; typically only single instances have been reported. Objective To report on a series of patients whose stent retriever thrombectomy was complicated by intraprocedural vessel perforation and discuss its potential mechanisms, rescue treatment strategies, and clinical significance. Methods Cases with intraprocedural vessel perforation, where a stent retriever was used either as a primary treatment approach or as a part of a direct aspiration first pass technique (ADAPT), were included in the final analysis. Clinical data, procedural details, radiographic and clinical outcomes were collected from nine participating centers. Results Intraprocedural vessel perforation during stent retriever thrombectomy occurred in 16 (1.0%) of 1599 cases. 63% of intraprocedural perforations occurred at distal locations. Endovascular rescue techniques (most commonly, intracranial balloon occlusion for tamponade) were attempted in 50% of cases. Procedure was aborted without any rescue attempts in 44% of cases. Mortality during hospitalization and at 3 months was 56% and 63%, respectively. 25% of patients achieved good functional outcome at 3 months after the procedure. Conclusions Intraprocedural perforations during stent retriever thrombectomy were rare, but when they occurred were associated with high mortality. Perforations most commonly occurred at distal occlusion sites and were often characterized by difficulty traversing the occlusion with a microcatheter or microwire, or while withdrawing the stent retriever. Nevertheless, 25% of patients had a favorable functional outcome, suggesting that in some patients with this complication good neurological recovery is achievable.

Endovascular treatment for AIS with underlying ICAD

Abstract: Background Acute large vessel occlusion (LVO) can result from thromboemboli or underlying intracranial atherosclerotic disease (ICAD). Although the technique for revascularization differs significantly for these two lesions (simple thrombectomy for thromboemboli and balloon angioplasty and stenting for ICAD), the underlying etiology is often unknown in acute ischemic stroke (AIS). Objective To evaluate whether procedural complications, revascularization rates, and functional outcomes differ among patients with LVO from ICAD or thromboembolism. Methods A retrospective review of thrombectomy cases from 2008 to 2015 was carried out for cases of AIS due to underlying ICAD. Thirty-six patients were identified. A chart and imaging review was performed to determine revascularization rates, periprocedural complications, and functional outcomes. Patients with ICAD and acute LVO were compared with those with underlying thromboemboli. Results Among patients with ICAD and LVO, mean National Institutes of Health Stroke Scale (NIHSS) score on admission was 12.9±8.5, revascularization (Thrombolysis In Cerebral Infarction, TICI ≥2b) was achieved in 22/34 (64.7%) patients, 11% had postprocedural intracerebral hemorrhage (PH2), and 14/33 (42.4%) had achieved a modified Rankin Scale (mRS) score of 0–2 at the 3-month follow-up. Compared with patients without underlying ICAD, there was no difference in NIHSS on presentation, or in the postprocedural complication rate. However, procedure times for ICAD were longer (98.5±59.8 vs 37.1±34.2 min), there was significant difference in successful revascularization rate between the groups (p=0.001), and a trend towards difference in functional outcome at 3 months (p=0.07). Conclusions Despite AIS with underlying ICAD requiring a more complex, technically demanding recanalization strategy than traditional thromboembolic AIS, it appears safe, and good outcomes are obtainable.

Long term experience using the ADAPT technique for the treatment of acute ischemic stroke.

Abstract: Introduction The direct aspiration first pass technique (ADAPT) has been introduced as a simple and fast method for achieving good angiographic and clinical outcomes using large bore aspiration catheters for the treatment of acute ischemic stroke (AIS). We present a single center9s long term experience with ADAPT. Methods Retrospective analysis of a database was gathered on patients undergoing stroke thrombectomy with ADAPT at a stroke center. Specific parameters captured included age, gender, National Institutes of Health Stroke Scale (NIHSS) score at presentation, time to presentation from last normal, and modified Rankin Scale (mRS) score at the 90 day follow-up. Radiological and angiographic imaging was reviewed to document the location of the vascular occlusion, Thrombolysis in Cerebral Infarction (TICI) flow postprocedure, and procedural complications. Results 191 consecutive patients who suffered an AIS treated with ADAPT were reviewed; 91 were women, and mean age was 67 years. Patients presented with a mean NIHSS score of 15.4, and 71 patients received intravenous tissue plasminogen activator. The average time from onset to puncture was 7.8 h. The average time for recanalization was 37.3 min. TICI 2B or better recanalization was achieved in 180 (94.2%) patients. 98 (54.1%) patients had an mRS of 0–2 at 90 days. Direct aspiration alone was performed in 145 cases, and 43 cases required the additional use of a stent retriever. There was no significant difference in presenting NIHSS score, average time to presentation, average mRS at 90 days, or 90 day mortality between the two groups. Time to recanalization was 29.6 min for direct aspiration compared with 61.4 min in cases that required adjunct devices (p=0.00000201). 79 (57.7%) patients who underwent direct aspiration only achieved a good outcome at 90 days (mRS 0–2) compared with 19 (43.2%) who underwent adjunct therapies (p=0.12). Conclusions ADAPT is an effective method to achieve good clinical and angiographic outcomes, and serves as a useful firstline method for revascularization.

Stroke care: initial data from a county-based bypass protocol for patients with acute stroke

Abstract: Background Early identification and transfer of patients with acute stroke to a primary or comprehensive stroke center results in favorable outcomes. Objective To describe implementation and results of an emergency medical service (EMS)-driven stroke protocol in Lucas County, Ohio. Method All county EMS personnel (N=464) underwent training in the R apid A rterial o C clusion E valuation (RACE) score. The RACE Alert (RA) protocol, whereby patients with stroke and a RACE score ≥5 were taken to a facility that offered advanced therapy, was implemented in July 2015. During the 6-month study period, 109 RAs were activated. Time efficiencies, diagnostic accuracy, and mechanical thrombectomy (MT) outcomes were compared with standard ‘stroke-alert’ (N=142) patients from the preceding 6 months. Results An increased treatment rate (25.6% vs 12.6%, p Conclusions Our results indicate that EMS adaptation of the RA protocol within Lucas County is feasible and effective for early triage and treatment of patients with stroke. Using this protocol, we can significantly improve treatment times for both systemic thrombolysis and MT.

How safe and effective are existing treatments for wide-necked bifurcation aneurysms? Literature-based objective performance criteria for safety and effectiveness.

Abstract: Introduction Wide-necked bifurcation aneurysms (WNBAs) present unique technical challenges for both endovascular and surgical treatments which aim to achieve complete occlusion of the aneurysm without compromising the patency of the incorporated regional parent vessels. We present a meta-analysis of traditional therapies for WNBAs to provide critical benchmarks for safety and effectiveness. Methods Following a systematic search of the literature and the application of pre-specified appropriateness criteria, 43 (including 2794 aneurysms treated) and 65 (including 5366 patients treated) references with sufficient detail were identified to include in a meta-analysis of efficacy and safety, respectively. Effectiveness endpoints of both complete and adequate occlusion were assessed. A composite safety endpoint was based upon commonly applied metrics for major adverse events. Fleiss analyses were performed for both effectiveness and safety endpoints for the entire group, and then parsed separately by treatment modality (surgical clipping (SC) or endovascular therapy (EVT)) and location (anterior or posterior circulation). Results Using the above methods, the core laboratory adjusted rate of complete occlusion was 46.3% (standard error 3.6%), 39.8% (3.7%), and 52.5% (9.6%) for all therapies, EVT, and SC, respectively. The rate of adequate occlusion was 59.4% (12.2%), 43.8% (5.3%), and 69.7% (14.3%) for all therapies, EVT, and SC, respectively. The rates of occurrence for pre-specified safety endpoints were 18.7% (2.9%), 21.1% (2.8%), and 24.3% (4.9%) for all therapies, EVT, and SC, respectively. Conclusions Conventional therapies for WNBAs are associated with relatively low rates of complete occlusion and peri-procedural complications are not uncommon. As new treatment technologies are investigated, it is important that the available data regarding predicate treatments is understood.

Mechanical thrombectomy for pediatric acute ischemic stroke: review of the literature

Abstract: Objective Given recent strongly positive randomized controlled adult mechanical thrombectomy trials, we sought to perform a comprehensive review of available literature on IA pediatric stroke intervention, with a focus on modern mechanical devices. Methods PubMed search for pediatric patients undergoing IA treatment of acute ischemic stroke (AIS) using modern devices between 2008 and 2015. 29 patients were included in this analysis. Results Average age was 10.3 years, 74.1% male, middle cerebral and basilar arteries represented 89.6% of 36 occluded vessels, and average pediatric stroke scale score of 18.1. Average time from symptom onset to intervention was 8.8 hours and 13.8% of patients received IV tissue plasminogen activator prior to mechanical thrombectomy. Stent retrievers were used in 58.6% of cases, the Penumbra system in 34.5%, and the Merci device in 27.6%. Modified Thrombolysis In Cerebral Infarction 2b/3 recanalization was achieved in 75.9% of cases. There were no major adverse events related to the intervention, although one procedure was associated with device malfunction without a definite change in long-term outcome. The average modified Rankin Scale (mRS) score was Conclusions This study suggests that mechanical thrombectomy in pediatric patients presenting with high pediatric NIH Stroke Scale scores and proximal large vessel occlusion is associated with high recanalization rates and excellent clinical outcome, although this is a retrospective review and the sample size is too small to make any definitive conclusions. This study provides class IVC evidence that endovascular treatment of pediatric AIS increases the chance of a good clinical outcome.

Endovascular treatment of intracranial aneurysms with the LVIS device: a systematic review.

Abstract: Objective Despite promising initial results, current knowledge regarding the use of the Low-profile Visualized Intraluminal Support (LVIS) device to treat wide-necked intracranial aneurysms is still limited. Our aim is to evaluate the feasibility, efficacy, and safety of the LVIS device in stent-assisted coiling of intracranial aneurysms. Methods We conducted a systematic review by searching PubMed, EMBASE, and Cochrane Library for all published studies on the treatment of intracranial aneurysms with the LVIS device up to March 2016. Feasibility was evaluated by the technical success rate during the procedure, efficacy was evaluated by the rate of complete aneurysm occlusion at follow-up angiography, and safety was assessed by procedure-related morbidity and mortality. Results A total of nine studies were included in the analysis, including 384 patients with 390 aneurysms. The overall technical success rate was 96.8% (95% CI 94.4% to 99.1%). The aneurysmal complete occlusion rate was 54.6% (95% CI 31.8% to 77.4%) on immediate control and 84.3% (95% CI 78.9% to 89.7%) at follow-up angiography. Procedural-related morbidity and mortality were 1.4% (95% CI 0.2% to 2.6%) and 0% (95% CI 0%), respectively. The thromboembolic event rate was 4.9% (95% CI 1.9% to 7.9%) and the hemorrhagic event rate was 2.1% (95% CI 0.7% to 3.5%), with 0.9% (95% CI 0% to 1.8%) experiencing neurologic hemorrhagic complications and 1.9% (95% CI 0.5% to 3.2%) experiencing non-neurologic hemorrhagic complications. Conclusions Our systematic review suggests that endovascular treatment of intracranial aneurysms with the LVIS device is feasible, safe, and effective in the short term. However, the rate of thromboembolic complications is not negligible. Further prospective studies are needed to evaluate the long-term efficacy and safety of the LVIS device.

Admission systolic blood pressure and outcomes in large vessel occlusion strokes treated with endovascular treatment

Abstract: Background and purpose High admission blood pressure (BP) levels have been associated with lower recanalization rates after endovascular treatment (EVT) for patients with acute ischemic stroke (AIS) with emergent large vessel occlusion (ELVO). We sought to evaluate the association of admission BP with early outcomes in patients with ELVO treated with EVT. Methods Consecutive patients with AIS presenting with ELVO in a tertiary stroke center during a 4-year period were prospectively evaluated. Admission systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using automated cuff recordings. A blinded neuroradiologist calculated the final infarct volume (FIV) using standardized ABC/2 methodology. A favorable functional outcome (FFO) at 3 months was defined as modified Rankin Scale score of 0–2. Results Our study population consisted of 116 patients with AIS (mean age 63±13 years, median NIH Stroke Scale score 17 points (IQR 14–21), median FIV 30 cm 3 (IQR 8–94)). Higher admission SBP correlated with higher FIV (r +0.225; p=0.020). Patients with FFO had lower admission SBP (151±24 mm Hg vs 165±28 mm Hg; p=0.010), while admission SBP levels were higher in patients who died during hospitalization (169±34 mm Hg vs 156±24 mm Hg; p=0.043). A 10 mm Hg increment in admission SBP was independently (p=0.010) associated with an increase of 12 cm 3 in FIV (95% CI 3 to 21) in multiple linear regression models adjusting for potential confounders. A 10 mm Hg increment in admission SBP was independently (p=0.012) associated with a lower likelihood of FFO at 3 months (OR 0.64; 95% CI 0.45 to 0.91) in multiple logistic regression models adjusting for potential confounders. Conclusions Higher admission SBP is an independent predictor of increased FIV and lower likelihood of 3-month FFO in patients with ELVO treated with EVT.

Treatment of complex anterior cerebral artery aneurysms with Pipeline flow diversion: mid-term results

Abstract: Background The off-label use of flow diverters in the treatment of distal aneurysms continues to be debated. Objective To report our multicenter experience in the treatment of complex anterior cerebral artery aneurysms with the Pipeline embolization device (PED). Methods The neurointerventional databases of the four participating institutions were retrospectively reviewed for aneurysms treated with PED between October 2011 and January of 2016. All patients treated for anterior cerebral artery aneurysms were included in the analysis. Clinical presentation, location, type, vessel size, procedural complications, clinical and imaging follow-up were included in the analysis. Results Twenty patients (13 female) with 20 aneurysms met the inclusion criteria in our study. Fifteen aneurysms were classified as saccular and five as fusiform (mean size 7.3 mm). Thirteen aneurysms were located in the anterior communicating region (ACOM or A1/2 junction), six were A2-pericallosal, and one was located in the A1 segment. Six patients had presented previously with subarachnoid hemorrhage and had their aneurysms initially clipped or coiled. There was one minor event (a small caudate infarct) and one major event (intraparenchymal hemorrhage). Sixteen of the 20 patients had angiographic follow-up (mean 10 months). Eleven aneurysms were completely occluded, one had residual neck, and four had residual aneurysm filling. Conclusions The treatment of complex anterior cerebral artery aneurysms with the PED as an alternative for patients who are not good candidates for conventional methods is technically feasible and safe. Mid-term results are promising but larger series with long-term follow-up are required to assess its effectiveness.

Thrombogenicity of flow diverters in an ex vivo shunt model: effect of phosphorylcholine surface modification

Abstract: Background Flow diverters offer a promising treatment for cerebral aneurysms However, they have associated thromboembolic risks, mandating chronic dual antiplatelet therapy (DAPT) Shield Technology is a phosphorylcholine surface modification of the Pipeline Embolization Device (PED) flow diverter, which has shown significant reductions in material thrombogenicity in vitro Objective To compare the thrombogenicity of PED, PED with Shield Technology (PED+Shield), and the Flow-Redirection Endoluminal Device (FRED)—with and without single antiplatelet therapy and DAPT—under physiological flow Methods An established non-human primate ex vivo arteriovenous shunt model of stent thrombosis was used PED, PED+Shield, and FRED were tested without antiplatelet therapy, with acetylsalicylic acid (ASA) monotherapy, and with DAPT Radiolabeled platelet deposition was quantified over 1 hour for each device and total fibrin deposition was also quantified Results Cumulative statistical analysis showed significantly lower platelet deposition on PED compared with FRED The same statistical model showed significant decreases in platelet deposition when ASA, clopidogrel, or Shield Technology was used Direct comparisons of device performances within antiplatelet conditions showed consistent significant decreases in platelet accumulation on PED+Shield relative to FRED PED+Shield showed significant reductions in platelet deposition compared with unmodified PED without antiplatelet therapy and with DAPT PED accumulated minimal fibrin with and without Shield Technology Conclusions In this preclinical model, we have shown that the Shield Technology phosphorylcholine modification reduces the platelet-specific thrombogenicity of a flow diverter under physiologically relevant flow with and without DAPT We have further identified increased fibrin-driven thrombogenicity associated with FRED relative to PED

Streamlining door to recanalization processes in endovascular stroke therapy

Abstract: Background In acute stroke due to large vessel occlusion, faster reperfusion leads to better outcomes. We analyzed the effect of optimization steps aimed to reduce treatment delays at our center. Methods Consecutive patients with ischemic stroke treated with endovascular therapy were prospectively analyzed. We divided the patients into pre-optimization (20 April 2012 to 8 October 2013) and post-optimization (9 October 2013 to 29 July 2014) periods. The main interventions included: (1) continuous feedback; (2) standardized immediate emergency department attending to stroke attending communication with interventional team activation for all potential interventions; (3) pre-notification by the emergency medical service; (4) minimizing additional diagnostic testing; (5) direct transport to the CT scanner; (6) transport directly from the CT scanner to the angiography suite. The main metric used to measure improvement was door to groin puncture time (D2P). Results We included a total of 286 patients (178 pre-optimization, 108 post-optimization). There were no significant differences between major baseline characteristics between the groups with the exception of higher median CT Alberta Stroke Program Early CT Score in the pre-optimization group (p=0.01). Median D2P improved from 105 min pre-optimization to 67 min post-optimization (p=0.0002). Rates of good clinical outcomes (modified Rankin Scale 0–2 at 3 months) were similar in both groups, with a trend toward a better outcome in the post-optimization group in a subgroup analysis of patients with anterior circulation occlusion who received intravenous tissue plasminogen activator. Conclusions This pilot study demonstrates that D2P times can be significantly reduced with a standardized multidisciplinary approach. There was no significant difference in the rate of 3-month good outcome, which is most likely due to the small sample size and confounding baseline patient characteristics.

Prehospital care delivery and triage of stroke with emergent large vessel occlusion (ELVO): report of the Standards and Guidelines Committee of the Society of Neurointerventional Surgery

Abstract: Recent randomized clinical trials1–5 established the superiority of endovascular recanalization techniques, specifically mechanical embolectomy, compared with best medical therapy alone for the treatment of patients with emergent large vessel occlusion (ELVO) stroke. ELVO stroke is defined as a stroke secondary to anterior circulation large vessel occlusion (LVO) of the internal carotid, middle cerebral (M1 segments) arteries documented by imaging, without large completed infarct and presenting within 6 hours of symptom onset.6 Given the overwhelming clinical evidence provided by these trials, recent American Heart Association (AHA) guidelines concluded that “embolectomy needs to be performed as rapidly as possible for the greatest clinical benefit, and is best when performed within 6 h from onset of symptoms” (AHA class I, level of evidence A).6 In addition, cost modeling derived from trial outcomes data and claims databases in the USA strongly suggests that cost-effectiveness and an overall societal benefit is associated with investment in access to these endovascular techniques.7 Rapid access to endovascular services depends upon optimization of prehospital stroke care and transport within stroke systems of care, focusing on the unique needs of patients with ELVO through their diagnostic investigation and treatment pathway. The Society of NeuroInterventional Surgery (SNIS) proposed process time metrics for ELVO stroke treatment, including door to IV tissue plasminogen activator (t-PA) of <30 min, comprehensive stroke center (CSC) door to puncture of <60 min, CSC door to recanalization of <90 min and primary stroke certification (PSC) picture to CSC puncture of <90 min.8 Early team awareness of the patient with potential ELVO, coupled with efficient interdisciplinary communication, triage and transport assist in meeting these ideal time metrics, and also contribute to improved clinical outcomes through efficiency gains and maximization of endovascular care delivery. The Standards and Guidelines Committee of the SNIS, a multidisciplinary society representing leaders in the field of …

Hospital transfer associated with increased mortality after endovascular revascularization for acute ischemic stroke

Abstract: Background Patients with an acute ischemic stroke (AIS) due to large vessel occlusion often require transfer to an endovascular center for treatment. Objective To assess the effect of hospital transfer on outcomes after endovascular revascularization. Methods Outcomes of endovascular revascularization were compared between directly admitted and transferred patients using data from a national database and our own institution. Results 118 institutions within the database reported outcomes of 8533 inpatient admissions for endovascular treatment of AIS. Mortality rate (14.9% vs 18.6%; p=0.049) and mortality index (1.1 vs 1.6; p=0.048) were significantly lower among directly admitted patients than among transferred patients. Within our institutional cohort of 140 patients who underwent endovascular therapy, directly admitted patients had a significantly faster time to revascularization than transferred patients (277.4 vs 420.4 min; p≤0.0001). Among transferred patients, an increasing distance of transferred hospital to our home institution was associated with an increasing risk of mortality (unit OR=1.26, 95% CI 1.07 to 1.54; p=0.0061). Conclusions Outcomes of revascularization may improve with methods to identify patients with large vessel occlusion before hospital admission, thus increasing the likelihood of initial triage to a comprehensive stroke center for patients eligible for endovascular intervention.

Periprocedural outcomes and early safety with the use of the Pipeline Flex Embolization Device with Shield Technology for unruptured intracranial aneurysms: preliminary results from a prospective clinical study

Abstract: Background and purpose The Pipeline Embolization Device (PED) has become a routine first-line option for treatment of intracranial aneurysms (IAs). We assessed the early safety and technical success of a new version of PED, Pipeline Flex Embolization Device with Shield Technology (Pipeline Shield), which has the same design and configuration but has been modified to include a surface synthetic biocompatible polymer. Materials and methods The Pipeline Flex Embolization Device with Shield Technology (PFLEX) study is a prospective, single-arm, multicenter study for the treatment of unruptured IAs using Pipeline Shield. The primary study endpoints included the occurrence of major stroke in the territory supplied by the treated artery or neurologic death at 1 year post-procedure. Secondary endpoints included the rate of Pipeline Shield-related or procedure-related serious or non-serious adverse events. Analyses were conducted to evaluate early safety findings in the 30-day post-procedure period as well as technical procedural success outcomes. Results Fifty patients with 50 unruptured target IAs were enrolled. Mean aneurysm diameter was 8.82±6.15 mm. Thirty-eight aneurysms (76%) were small ( Conclusions The results of this first experience with the new Pipeline Flex corroborate the early safety of the device. Mid-term and long-term follow-up examinations will provide data on safety outcomes at the 6-month and 1-year follow-up periods. Clinical trial registration NCT02390037.