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Background Several studies have established the safety and efficacy of balloon guide catheters (BGCs) for large vessel occlusions. However, the utility of BGCs remains largely unexplored for distal medium vessel occlusions (DMVOs). In this study, we aim to compare the outcomes of BGC vs. Non-BGC in patients undergoing mechanical thrombectomy (MT) for DMVO. Method This retrospective study from the Stroke Thrombectomy and Aneurysm Registry (STAR) encompassed adult patients with acute anterior cerebral artery, posterior cerebral artery, and middle cerebral artery-M2--3--4 occlusions. Procedure times, safety, recanalization, and neurological outcomes were compared between the two groups, with subgroup analysis based on first-line thrombectomy techniques. Results A total of 1508 patients were included, with 231 patients (15.3%) in the BGC group and 1277 patients (84.7%) in the non-BGC group. The BGC group had a lower modified Thrombolysis in Cerebral Infarction (mTICI) score ≥2C (43.2% vs 52.7%, P=0.01), longer time from puncture to intracranial access (15 vs 8 min, P<0.01), and from puncture to final recanalization (97 vs 34 min, P<0.01). In the Solumbra subgroup, the first pass effect (FPE) rate was lower in the BGC group (17.4% vs 30.7%, P=0.03). Regarding clinical outcomes, the BGC group had a lower rate of distal embolization (8.8% vs 14.9%, P=0.03). Conclusion Our study found that use of BGC in patients with DMVO was associated with lower mTICI scores, decreased FPE rates, reduced distal embolization, and longer procedure times. [ABSTRACT FROM AUTHOR]

Background Tools predicting intracranial dural arteriovenous fistulas (dAVFs) treatment outcomes remain scarce. This study aimed to use a multicenter database comprising more than 1000 dAVFs to develop a practical scoring system that predicts treatment outcomes. Methods Patients with angiographically confirmed dAVFs who underwent treatment within the Consortium for Dural Arteriovenous Fistula Outcomes Research-participating institutions were retrospectively reviewed. A subset comprising 80% of patients was randomly selected as training dataset, and the remaining 20% was used for validation. Univariable predictors of complete dAVF obliteration were entered into a stepwise multivariable regression model. The components of the proposed score (VEBAS) were weighted based on their ORs. Model performance was assessed using receiver operating curves (ROC) and areas under the ROC. Results A total of 880 dAVF patients were included. Venous stenosis (presence vs absence), elderly age (<75 vs ≥75 years), Borden classification (I vs II-III), arterial feeders (single vs multiple), and past cranial surgery (presence vs absence) were independent predictors of obliteration and used to derive the VEBAS score. A significant increase in the likelihood of complete obliteration (OR=1.37 (1.27-1.48)) with each additional point in the overall patient score (range 0-12) was demonstrated. Within the validation dataset, the predicted probability of complete dAVF obliteration increased from 0% with a 0-3 score to 72-89% for patients scoring ≥8. Conclusion The VEBAS score is a practical grading system that can guide patient counseling when considering dAVF intervention by predicting the likelihood of treatment success, with higher scores portending a greater likelihood of complete obliteration. [ABSTRACT FROM AUTHOR]

Background The safety and efficacy of bridging therapy with intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) in patients with large core infarct has not been sufficiently studied. In this study, we compared the efficacy and safety outcomes between patients who received IVT+MT and those treated with MT alone. Methods This is a retrospective analysis of the Stroke Thrombectomy Aneurysm Registry (STAR). Patients with Alberta Stroke Program Early CT Score (ASPECTS) ≤5 treated with MT were included in this study. Patients were divided into two groups based on pre-treatment IVT (IVT, no IVT). Propensity score matched analysis were used to compare outcomes between groups. results A total of 398 patients were included; 113 pairs were generated using propensity score matching analyses. Baseline characteristics were well balanced in the matched cohort. The rate of any intracerebral hemorrhage (ICH) was similar between groups in both the full cohort (41.4% vs 42.3%, P=0.85) and matched cohort (38.55% vs 42.1%, P=0.593). Similarly, the rate of significant ICH was similar between the groups (full cohort: 13.1% vs 16.9%, P=0.306; matched cohort: 15.6% vs 18.95, P=0.52). There was no difference in favorable outcome (90-day modified Rankin Scale 0-2) or successful reperfusion between groups. In an adjusted analysis, IVT was not associated with any of the outcomes. Conclusion Pretreatment IVT was not associated with an increased risk of hemorrhage in patients with large core infarct treated with MT. Future studies are needed to assess the safety and efficacy of bridging therapy in patients with large core infarct. [ABSTRACT FROM AUTHOR]

Background Recent clinical trials have shown that mechanical thrombectomy is superior to medical management for large vessel occlusion for up to 24 hours from onset. Our objective is to examine the safety and efficacy of thrombectomy beyond the standard of care window. Methods A retrospective review was undertaken of the multicenter Stroke Thrombectomy and Aneurysm Registry (STAR). We identified patients who underwent mechanical thrombectomy for large vessel occlusion beyond 24 hours. We selected a matched control group from patients who underwent thrombectomy in the 6-24-hour window. We used functional independence at 3 months as our primary outcome measure. results We identified 121 patients who underwent thrombectomy beyond 24 hours and 1824 in the 6-24-hour window. We selected a 2:1 matched group of patients with thrombectomy 6-24 hours as a comparison group. Patients undergoing thrombectomy beyond 24 hours were less likely to be independent at 90 days (18 (18.8%) vs 73 (34.9%), P=0.005). They had higher odds of mortality at 90 days in the adjusted analysis (OR 2.34, P=0.023). Symptomatic intracerebral hemorrhage and other complications were similar in the two groups. In a multivariate analysis only lower number of attempts was associated with good outcomes (OR 0.27, P=0.022). Conclusions Mechanical thrombectomy beyond 24 hours appears to be safe and tolerable with no more hemorrhages or complications compared with standard of care thrombectomy. Outcomes and mortality in this time window are worse compared with an earlier time window, but the rates of good outcomes may justify this therapy in selected patients. [ABSTRACT FROM AUTHOR]

Background Reducing intracranial hemorrhage (ICH) can improve patient outcome in acute ischemic stroke (AIS) intervention. We sought to identify ICH risk factors after AIS thrombectomy. Methods This is a retrospective review of the Stroke Thrombectomy and Aneurysm Registry (STAR) database. All patients who underwent AIS thrombectomy with available ICH data were included. Multivariable regression models were developed to identify predictors of ICH after thrombectomy. Subgroup analyses were performed stratified by symptom status and European Cooperative Acute Stroke Study (ECASS) grade. Results The study cohort comprised 6860 patients. Any ICH and symptomatic ICH (sICH) occurred in 25% and 7% of patients, respectively. Hemorrhagic infarction 1 (HI1) occurred in 36%, HI2 in 24%, parenchymal hemorrhage 1 (PH1) in 22%, and PH2 in 17% of patients classified by ECASS grade. Intraprocedural complications independently predicted any ICH (OR 3.8083, P<0.0001), PH1 (OR 1.9053, P=0.0195), and PH2 (OR 2.7347, P=0.0004). Race also independently predicted any ICH (black: OR 0.5180, P=0.0017; Hispanic: OR 0.4615, P=0.0148), sICH (non- white: OR 0.4349, P=0.0107), PH1 (non-white: OR 3.1668, P<0.0001), and PH2 (non- white: OR 1.8689, P=0.0176), with white as the reference. Primary mechanical thrombectomy technique also independently predicted ICH. ADAPT (A Direct Aspiration First Pass Technique) was a negative predictor of sICH (OR 0.2501, P<0.0001), with stent retriever as the reference. Conclusions This study identified ICH risk factors after AIS thrombectomy using real-world data. There was a propensity towards a reduced sICH risk with direct aspiration. Procedural complications and ethnicity were predictors congruent between categories of any ICH, sICH, PH1, and PH2. Further investigation of technique and ethnicity effects on ICH and outcomes after AIS thrombectomy is warranted. [ABSTRACT FROM AUTHOR]

Background Endovascular thrombectomy (EVT) has become the mainstay treatment for large vessel occlusion, with favorable safety and efficacy profile. However, the safety and efficacy of EVT in concurrent multi-territory occlusions (MTVOs) remains unclear. Objective To investigate the prevalence, clinical and technical outcomes of concurrent EVT for MTVOs. Methods Data were included from the Stroke Thrombectomy and Aneurysm Registry (STAR) with 32 stroke centers for EVT performed to treat bilateral anterior or concurrent anterior and posterior circulation occlusions between 2017 and 2021. Patients with MTVO were identified, and propensity score matching was used to compare this group with patients with occlusion in a single arterial territory. Results Of a total of 7723 patients who underwent EVT for acute ischemic stroke, 54 (0.7%) underwent EVT for MTVOs (mean age 69±12.5; female 50%). 28% had bilateral and 72% had anterior and posterior circulations occlusions. The rate of successful recanalization (Thrombolysis in Cerebral Infarction 2b/3), complications, modified Rankin score at 90 days, and mortality was not significantly different between the matched cohorts. Multivariate analysis confirmed that MTVOs were not associated with poor functional outcome, symptomatic intracranial hemorrhage, or longer procedure time. Conclusion Compared with EVT for single vessel occlusions, EVT in appropriately selected patients with MTVOs has a similar efficacy and safety profile. [ABSTRACT FROM AUTHOR]

Background Endovascular thrombectomy (EVT) is the standard-of-care for proximal large vessel occlusion (LVO) stroke. Data on technical and clinical outcomes in distal vessel occlusions (DVOs) remain limited. Methods This was a retrospective study of patients undergoing EVT for stroke at 32 international centers. Patients were divided into LVOs (internal carotid artery/M1/vertebrobasilar), medium vessel occlusions (M2/A1/P1) and isolated DVOs (M3/M4/A2/A3/P2/P3) and categorized by thrombectomy technique. Primary outcome was a good functional outcome (modified Rankin Scale ≤2) at 90 days. Secondary outcomes included recanalization, procedure-time, thrombectomy attempts, hemorrhage, and mortality. Multivariate logistic regressions were used to evaluate the impact of technical variables. Propensity score matching was used to compare outcome in patients with DVO treated with aspiration versus stent retriever Results We included 7477 patients including 213 DVOs. Distal location did not independently predict good functional outcome at 90 days compared with proximal (p=0.467). In distal occlusions, successful recanalization was an independent predictor of good outcome (adjusted odds ratio (aOR) 5.11, p<0.05) irrespective of technique. Younger age, bridging therapy, and lower admission National Institutes of Health Stroke Scale (NIHSS) were also predictors of good outcome. Procedure time ≤1 hour or ≤3 thrombectomy attempts were independent predictors of good outcomes in DVOs irrespective of technique (aOR 4.5 and 2.3, respectively, p<0.05). There were no differences in outcomes in a DVO matched cohort of aspiration versus stent retriever. Rates of hemorrhage and good outcome showed an exponential relationship to procedural metrics, and were more dependent on time in the aspiration group and attempts in the stent retriever group. Conclusions Outcomes following EVT for DVO are comparable to LVO with similar results between techniques. Techniques may exhibit different futility metrics; stent retriever thrombectomy was influenced by attempts whereas aspiration was more dependent on procedure time. [ABSTRACT FROM AUTHOR]

Background Anterior cranial fossa dural arteriovenous fistulas (ACF-dAVFs) are aggressive vascular lesions. The pattern of venous drainage is the most important determinant of symptoms. Due to the absence of a venous sinus in the anterior cranial fossa, most ACF-dAVFs have some degree of drainage through small cortical veins. We describe the natural history, angiographic presentation and outcomes of the largest cohort of ACF-dAVFs. Methods The CONDOR consortium includes data from 12 international centers. Patients included in the study were diagnosed with an arteriovenous fistula between 1990-2017. ACF-dAVFs were selected from a cohort of 1077 arteriovenous fistulas. The presentation, angioarchitecture and treatment outcomes of ACF-dAVF were extracted and analyzed. Results 60 ACF-dAVFs were included in the analysis. Most ACF-dAVFs were symptomatic (38/60, 63%). The most common symptomatic presentation was intracranial hemorrhage (22/38, 57%). Most ACF-dAVFs drained through cortical veins (85%, 51/60), which in most instances drained into the superior sagittal sinus (63%, 32/51). The presence of cortical venous drainage predicted symptomatic presentation (OR 9.4, CI 1.98 to 69.1, p=0.01). Microsurgery was the most effective modality of treatment. 56% (19/34) of symptomatic patients who were treated had complete resolution of symptoms. Improvement of symptoms was not observed in untreated symptomatic ACF-dAVFs. Conclusion Most ACF-dAVFs have a symptomatic presentation. Drainage through cortical veins is a key angiographic feature of ACF-dAVFs that accounts for their malignant course. Microsurgery is the most effective treatment. Due to the high risk of bleeding, closure of ACF-dAVFs is indicated regardless of presentation. [ABSTRACT FROM AUTHOR]

Background Most intracranial stents contain nickel alloy, and nickel allergy or hypersensitivity is common. Neurological injury following endovascular treatment with a nickel containing intracranial stent has been reported in patients with purported nickel allergy, but it is unclear whether these reactions represent true nickel hypersensitivity. We quantified nickel release from commonly used intracranial stents to investigate whether such stents should be avoided in patients with nickel allergy. Methods We examined nickel release from seven commonly used intracranial stents: Enterprise, LVIS Jr, Neuroform, Wingspan, Zilver, Pipeline Flex Embolization Device, and Surpass Evolve. We incubated each stent in human plasma-like media for 30 days. Dimethylglyoxime (DMG) spot testing was performed on each stent to detect released nickel at 0 and 30 days. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) was then used to quantify the nickel concentration of the media at 30 days. Nickel currency and nickel standard for atomic absorption spectrometry were used as positive controls. Results DMG spot tests indicated nickel release only from nickel currency at 0 and 30 days of incubation. No nickel release was detected from any stent at 30 days using ICP-OES. Conclusions Nickel release from commonly used intracranial stents is negligible. These results suggest that previously reported hypersensitivity to these stents may be misattributed to nickel allergy, and that patients with nickel allergy may be safely treated with select nickel-containing stents. [ABSTRACT FROM AUTHOR]

Background M2 segment occlusions represent approximately one-third of non-lacunar ischemic stroke and can lead to permanent neurological deficits. Various techniques are available for mechanical thrombectomy beyond the circle of Willis, but data evaluating their effectiveness and safety are lacking. Methods A retrospective review of patients with ischemic stroke undergoing mechanical thrombectomy for M2 occlusions from 13 centers in North American and Europe was performed. Tandem or multiple-territory occlusions were excluded. The primary outcome was 90-day modified Rankin Scale and reperfusion rates across stent-retriever, direct aspiration and combined techniques. Results There were 465 patients (mean age 71.48±14.03 years, 53.1% female) with M2 occlusions who underwent mechanical thrombectomy. Stentretriever alone was used in 133 (28.6%), direct aspiration alone in 93 (20.0%) and the combined technique in 239 (51.4%) patients. Successful reperfusion was achieved with the combined technique in 198 (82.2%; OR 2.6 (1.1-6.9)), with stent-retriever alone in 112 (84.2%; OR 9.2 (1.9-44.6)) and with direct aspiration alone in 62 (66.7%; referencecategory). Intraprocedural subarachnoid hemorrhages (iSAH) were 36 (7.7%) and were more likely to occur in patients treated with the stent-retrievers (OR 5.0 (1.1-24.3)) and combined technique (OR 4.6 (1.1-20.9)). Good clinical outcome was achieved in 260 (61.8%) patients, while 59 (14.0%) patients died. Older age, higher baseline NIHSS (National Institutes of Health Stroke Scale), parenchymal hemorrhage and iSAH were associated with poor outcome while successful recanalization and higher baseline ASPECTS (Alberta Stroke Program Early CT Score) were associated with good outcome. No differences were found among the three techniques in terms of clinical outcome. Conclusion Stent-retrievers and a combined approach for M2 occlusions seem more effective than direct aspiration, but with higher rates of iSAH. This leads to no detectable difference in clinical outcome at 3 months. [ABSTRACT FROM AUTHOR]

Background Although the liquid embolic agent, Onyx, is often the preferred embolic treatment for cerebral dural arteriovenous fistulas (DAVFs), there have only been a limited number of single-center studies to evaluate its performance. Objective To carry out a multicenter study to determine the predictors of complications, obliteration, and functional outcomes associated with primary Onyx embolization of DAVFs. Methods From the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database, we identified patients who were treated for DAVF with Onyx-only embolization as the primary treatment between 2000 and 2013. Obliteration rate after initial embolization was determined based on the final angiographic run. Factors predictive of complete obliteration, complications, and functional independence were evaluated with multivariate logistic regression models. Results A total 146 patients with DAVFs were primarily embolized with Onyx. Mean follow-up was 29 months (range 0-129 months). Complete obliteration was achieved in 80 (55%) patients after initial embolization. Major cerebral complications occurred in six patients (4.1%). At last followup, 84% patients were functionally independent. Presence of flow symptoms, age over 65, presence of an occipital artery feeder, and preprocedural home anticoagulation use were predictive of non-obliteration. The transverse-sigmoid sinus junction location was associated with fewer complications, whereas the tentorial location was predictive of poor functional outcomes. Conclusions In this multicenter study, we report satisfactory performance of Onyx as a primary DAVF embolic agent. The tentorium remains a more challenging location for DAVF embolization, whereas DAVFs located at the transverse- sigmoid sinus junction are associated with fewer complications. [ABSTRACT FROM AUTHOR]

Background Although studies continue to demonstrate lower complications in neurointerventions using transradial access (TRA) compared with transfemoral approaches, anatomic radial variants can be difficult to navigate and remain one of the frequent causes of access site conversion. Objective To evaluate predictors of TRA failure in neuroendovascular patients with radial loops and suggest a protocol for managing these anomalies. Methods A prospective collection of patients undergoing TRA at participating institutions from July 2018 to September 2020 was reviewed. Patients with a radial loop were identified. Patient demographics and procedural characteristics were evaluated to determine predictors of both TRA failure and successful reduction of the radial loop. Results We identified 32 transradial neurointerventions in which patients had radial loops. Twenty-two (68.8%) were identified by diagnostic angiography, and the majority were performed for evaluation or treatment of an aneurysm (56.3%). TRA failure occurred in 13 (40.6%) of the cohort and happened more frequently in patients over 60 years of age (p=0.01) and those with recurrent radial artery diameters ≤2 mm (p=0.02). Of the 19 patients who had successful TRA, 12 (63.2%) procedures were performed through the recurrent radial artery. Conclusion Although radial loops are associated with high transradial failure rates, our results suggest that the presence of a loop is not an absolute contraindication to TRA. Therefore, we recommend attempting loop navigation using our protocol. Patient age, vascular tortuosity, and recurrent radial artery size should help dictate when to convert to an alternative access site. conversion when the loop cannot be traversed or reduced successfully. [ABSTRACT FROM AUTHOR]

Background Antiplatelet therapy is used to prevent stent thrombosis in intracranial stents, but the optimal dose of aspirin is unknown. This study sought to determine whether the degree of platelet inhibition with aspirin is affected by bodyweight as observed through a platelet reactivity assay. Methods This is a retrospective review of patients who underwent neurovascular stent placement and had a VerifyNow Aspirin assay result. The primary outcome was the correlation between the VerifyNow Aspirin result, bodyweight, and the initial dose of aspirin. Secondary outcomes included the impact of the VerifyNow P2Y12 result and of weight on the incidence of bleeding or a thrombotic event. Results Of the 142 included patients, 62.7% weighed ≥70 kg and 88.7% were initiated on aspirin 300-325 mg daily. 83.8% achieved a therapeutic VerifyNow Aspirin result. There was minimal correlation between the VerifyNow Aspirin result, bodyweight, and aspirin dose (R²=0.02). Between patients who weighed <70 kg versus ≥70 kg, there was no difference in the mean aspirin reaction units (ARU) (449 vs 435, p=0.32) or in the incidence of bleeding (28% vs 17.1%, p=0.14) or a thrombotic event (4% vs 5.3%, p=0.59). No patient experienced stent thrombosis and eight patients experienced in-stent stenosis. In a multivariate analysis, only the VerifyNow P2Y12 result predicted the development of either bleeding or a thrombotic event (p<0.01). Conclusions Bodyweight did not influence the likelihood of obtaining a therapeutic VerifyNow Aspirin result. The clinical utility of obtaining VerifyNow Aspirin assays for this patient population is unknown. [ABSTRACT FROM AUTHOR]

Background The transcirculation approach (TCA) for stent-assisted coiling (SAC) of intracranial aneurysms may be useful for certain wide-neck bifurcation aneurysms as well as those with acute-angle efferent branches. Objective To describe a multicenter experience using the TCA for SAC. Methods A multicenter, retrospective study (2016-2020) of aneurysm treatment using SAC via the TCA. Angiographic outcome was scored using the Raymond Scale (adequate occlusion 1 and 2), and clinical outcome was scored using a modified Rankin Scale (good outcome 0-2) Results Twenty-nine patients with 29 aneurysms were included (62.1% female; average age 61; 89.7% unruptured; 13.8% previously treated; average dome size 6.4 mm; average neck 4.4 mm). Aneurysm locations included internal carotid artery-fetal posterior cerebral artery (n=4), internal carotid artery terminus (n=4), anterior communicating artery (n=8), vertebral artery-posterior inferior cerebellar artery (n=2), and basilar tip (n=11). The TCA used communicating arteries (93.1%; average 1.6 mm), intermediate catheters (51.7%), jailing technique (62.1%), and staged procedures (10.3%). The most common stent was the Neuroform Atlas (Stryker; 69%). Immediate adequate occlusion was obtained in 75.9%, and five patients with inadequate occlusion progressed to adequate occlusion at follow-up. One (3.4%) procedural complication occurred: a watershed stroke in the setting of baseline four-vessel extracranial disease. Two patients had a poor outcome unrelated to the TCA. The majority of patients (86.4%) had a good clinical outcome. One case of in-stent stenosis due to non-compliance with medication was seen, which resolved with medication resumption. Conclusions The TCA for SAC can be performed for a variety of aneurysms with a low complication rate and good clinical outcomes. [ABSTRACT FROM AUTHOR]

Background Radial artery access for transarterial procedures has gained recent traction in neurointerventional due to decreased patient morbidity, technical feasibility, and improved patient satisfaction. Upper extremity transvenous access (UETV) has recently emerged as an alternative strategy for the neurointerventionalist, but data are limited. Our objective was to quantify the use of UETV access in neurointerventions and to measure failure and complication rates. Methods An international multicenter retrospective review of medical records for patients undergoing UETV neurointerventions or diagnostic procedures was performed. We also present our institutional protocol for obtaining UETV and review the existing literature. Results One hundred and thirteen patients underwent a total of 147 attempted UETV procedures at 13 centers. The most common site of entry was the right basilic vein. There were 21 repeat puncture events into the same vein following the primary diagnostic procedure for secondary interventional procedures without difficulty. There were two minor complications (1.4%) and five failures (ie, conversion to femoral vein access) (3.4%). Conclusions UETV is safe and technically feasible for diagnostic and neurointerventional procedures. Further studies are needed to determine the benefit over alternative venous access sites and the effect on patient satisfaction. [ABSTRACT FROM AUTHOR]

Objective The goal of this article is to provide a succinct review of the key components of a NIH grant application and the NIH reviewprocess for the early career neurointerventionalist. Methods The authors reviewed NIH rules and regulations and also reflected on their own collective experiencein writing NIH grant proposals in the area of cerebrovascular disease andneurointerventional surgery. Results Key components of theresearch strategy include specific aims, significance, innovation and approach. The specific aims page is the most important page of the application and should be written first. The NIH review isbased on these key components along with an assessment of the appropriatenessof the investigators and environment for the research. Conclusion Detailed knowledge ofthe key components of the research grant is critical to a successful application.The information in the article may aid in the grant writing for early careerneurointerventionalists. [ABSTRACT FROM AUTHOR]

Objective The goal of this article is to provide recommendations for the early career neurointerventionalist in writing a successful grant application to the National Institutes of Health (NIH) and similar funding agencies. Methods The authors reviewed NIH rules and regulations and also reflected on their own collective experience in writing NIH grant proposals in the area of cerebrovascular disease and neurointerventional surgery. Results A strong proposal should address an important scientific problem where there is a gap in knowledge. The solution offered needs to be innovative but at the same time based on a strong scientific premise. The proposed research must be feasible to implement and investigate in the researcher's environment. Conclusion Successful grant writing is critical in funding and enhancing research. The information in the article may aid in the preparation stage of grant writing for early career neurointerventionalists. [ABSTRACT FROM AUTHOR]

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

We report successful transvenous treatment of direct carotid--cavernous fistula in a patient with Ehlers--Danlos syndrome type IV using a novel triple-overlay embolization (TAILOREd) technique without the need for arterial puncture, which is known to be highly risky in this patient group. The TAILOREd technique allowed for successful treatment using preoperative MR angiography as a three-dimensional overlay roadmap combined with cone beam CT and live fluoroscopy, precluding the need for an arterial puncture. [ABSTRACT FROM AUTHOR]

Background The transradial approach (TRA) has gained increasing popularity for neuroendovascular procedures. However, the experience with TRA in neuroangiography is still in early stages in most centers, and the safety and feasibility of this approach have not been well established. The purpose of this study is to report the safety and feasibility of TRA for neuroendovascular procedures. Methods We reviewed charts from six institutions in the USA to include consecutive patients who underwent diagnostic or interventional neuroendovascular procedures through TRA from July 2018 to July 2019. Collected data included baseline characteristics, procedural variables, complications, and whether there was a crossover to transfemoral access. Results A total of 2203 patients were included in the study (age 56.1±15.2, 60.8% women). Of these, 1697 (77%) patients underwent diagnostic procedures and 506 (23%) underwent interventional procedures. Successfully completed procedures included aneurysm coiling (n=97), flow diversion (n=89), stent-assisted coiling (n=57), balloon-assisted coiling (n=19), and stroke thrombectomy (n=76). Crossover to femoral access was required in 114 (5.2%). There were no major complications related to the radial access site. Minor complications related to access site were seen in 14 (0.6%) patients. Conclusion In this early stage of transforming to the 'radial-first' approach for neuroendovascular procedures, TRA was safe with low complication rates for both diagnostic and interventional procedures. A wide range of procedures were completed successfully using TRA. [ABSTRACT FROM AUTHOR]

Background In response to the COVID-19 pandemic, many centers altered stroke triage protocols for the protection of their providers. However, the effect of workflow changes on stroke patients receiving mechanical thrombectomy (MT) has not been systematically studied. Methods A prospective international study was launched at the initiation of the COVID-19 pandemic. All included centers participated in the Stroke Thrombectomy and Aneurysm Registry (STAR) and Endovascular Neurosurgery Research Group (ENRG). Data was collected during the peak months of the COVID-19 surge at each site. Collected data included patient and disease characteristics. A generalized linear model with logit link function was used to estimate the effect of general anesthesia (GA) on in- hospital mortality and discharge outcome controlling for confounders. Results 458 patients and 28 centers were included from North America, South America, and Europe. Five centers were in high- COVID burden counties (HCC) in which 9/104 (8.7%) of patients were positive for COVID-19 compared with 4/354 (1.1%) in low-COVID burden counties (LCC) (P<0.001). 241 patients underwent pre- procedure GA. Compared with patients treated awake, GA patients had longer door to reperfusion time (138 vs 100 min, P=<0.001). On multivariate analysis, GA was associated with higher probability of in- hospital mortality (RR 1.871, P=0.029) and lower probability of functional independence at discharge (RR 0.53, P=0.015). Conclusion We observed a low rate of COVID-19 infection among stroke patients undergoing MT in LCC. Overall, more than half of the patients underwent intubation prior to MT, leading to prolonged door to reperfusion time, higher in-hospital mortality, and lower likelihood of functional independence at discharge. [ABSTRACT FROM AUTHOR]

Background Infection from the SARS-CoV-2 virus has led to the COVID-19 pandemic. Given the large number of patients affected, healthcare personnel and facility resources are stretched to the limit; however, the need for urgent and emergent neurosurgical care continues. This article describes best practices when performing neurosurgical procedures on patients with COVID-19 based on multi-institutional experiences. Methods We assembled neurosurgical practitioners from 13 different health systems from across the USA, including those in hot spots, to describe their practices in managing neurosurgical emergencies within the COVID-19 environment. Results Patients presenting with neurosurgical emergencies should be considered as persons under investigation (PUI) and thus maximal personal protective equipment (PPE) should be donned during interaction and transfer. Intubations and extubations should be done with only anesthesia staff donning maximal PPE in a negative pressure environment. Operating room (OR) staff should enter the room once the air has been cleared of particulate matter. Certain OR suites should be designated as covid ORs, thus allowing for all neurosurgical cases on covid/PUI patients to be performed in these rooms, which will require a terminal clean post procedure. Each COVID OR suite should be attached to an anteroom which is a negative pressure room with a HEPA filter, thus allowing for donning and doffing of PPE without risking contamination of clean areas. Conclusion Based on a multi-institutional collaborative effort, we describe best practices when providing neurosurgical treatment for patients with COVID-19 in order to optimize clinical care and minimize the exposure of patients and staff. This article is made freely available for use in accordance with BMJ's website terms and conditions for the duration of the covid-19 pandemic or until otherwise determined by BMJ. You may use, download and print the article for any lawful, non-commercial purpose (including text and data mining) provided that all copyright notices and trade marks are retained. [ABSTRACT FROM AUTHOR]

Background The COVID-19 pandemic has disrupted established care paths worldwide. Patient awareness of the pandemic and executive limitations imposed on public life have changed the perception of when to seek care for acute conditions in some cases. We sought to study whether there is a delay in presentation for acute ischemic stroke patients in the first month of the pandemic in the US. Methods The interval between last-known-well (LKW) time and presentation of 710 consecutive patients presenting with acute ischemic strokes to 12 stroke centers across the US were extracted from a prospectively maintained quality database. We analyzed the timing and severity of the presentation in the baseline period from February to March 2019 and compared results with the timeframe of February and March 2020. Results There were 320 patients in the 2-month baseline period in 2019, there was a marked decrease in patients from February to March of 2020 (227 patients in February, and 163 patients in March). There was no difference in the severity of the presentation between groups and no difference in age between the baseline and the COVID period. The mean interval from LKW to the presentation was significantly longer in the COVID period (603±1035 min) compared with the baseline period (442±435 min, P<0.02). Conclusion We present data supporting an association between public awareness and limitations imposed on public life during the COVID-19 pandemic in the US and a delay in presentation for acute ischemic stroke patients to a stroke center. This article is made freely available for use in accordance with BMJ's website terms and conditions for the duration of the covid-19 pandemic or until otherwise determined by BMJ. You may use, download and print the article for any lawful, non-commercial purpose (including text and data mining) provided that all copyright notices and trade marks are retained. [ABSTRACT FROM AUTHOR]

Introduction Transradial access is increasingly used among neurointerventionalists as an alternative to the transfemoral route. Currently available data, building on the interventional cardiology experience, primarily focus on right radial access. However, there are clinical scenarios when left-sided access may be indicated. The purpose of this study was to evaluate the technical feasibility of left transradial access to cerebral angiography across three institutions. Methods A retrospective chart review was performed for patients who underwent cerebral angiography accessed via the left radial artery at three institutions between January 2018 and July 2019. The outcome variables studied were successful catheterization, vascular complications, and fluoroscopic time. Results Nineteen patients underwent a total of 25 cerebral angiograms via left transradial access for cerebral aneurysms (n=15), basilar occlusion (n=1), carotid stenosis (n=1), arteriovenous malformation (n=1), and cervical neurofibroma (n=1). There were 12 diagnostic angiograms and 13 interventional angiograms. The left transradial approach was chosen due to left vertebrobasilar pathology (n=22), right subclavian stenosis (n=2), and previous right arm amputation (n=1). There was one instance of radial artery spasm, which resolved after catheter removal, and one conversion to transfemoral access in an interventional case due to lack of distal catheter support. There were no procedural complications. Conclusions Left transradial access in diagnostic and interventional cerebral angiography is a technically feasible, safe, and an effective alternative when indicated, and may be preferable for situations in which pathology locations or anatomic limitations preclude right-sided radial access. [ABSTRACT FROM AUTHOR]

Introduction Endovascular embolization of intracranial meningiomas is commonly used as an adjunct to surgical resection. We sought to describe the anatomic locations and vascular supplies of meningiomas to identify characteristics predictive of successful preoperative endovascular embolization. Methods We conducted a retrospective review of 139 meningioma cases receiving cerebral angiograms for possible preoperative endovascular embolization at our institution between December 2000 and March 2017. The extent of embolization, arterial supply, anatomic location, and procedural complications were recorded for each case. Univariate and multivariate analyses were performed to identify tumor characteristics that predicted successful embolization. results Of the total meningioma patients undergoing preoperative angiography, 78% (108/139) were successfully embolized, with a 2.8% periprocedural complication rate (3/108). Within the subset of patients with successful embolization, 31% (33/108) achieved complete angiographic embolization. Significant multivariate predictors of embolization (either partial or complete) were convexity/parasagittal locations (OR 5.15, 95% CI 0.93 to 28.54, p=0.060), meningohypophyseal trunk (MHT, OR 4.65, 95% CI 1.63 to 13.23, p=0.004), middle meningeal artery (MMA, OR 10.89, 95% CI 3.43 to 34.64, p<0.001), and ascending pharyngeal artery supply (APA, OR 9.96, 95% CI 1.88 to 52.73, p=0.007). Significant predictors for complete embolization were convexity/parasagittal locations (OR 4.79, 95% CI 1.66 to 13.84, p=0.004) and embolized APA supply (OR 6.94, 95% CI 1.90 to 25.39, p=0.003). Multiple arterial supply was a negative predictor of complete embolization (OR 0.38, 95% CI 0.15 to 0.98, p=0.05). Conclusions Tumor characteristics can be used to predict the likelihood of preoperative meningioma embolization. Parasagittal and convexity meningiomas, and those with APA supply, are most likely to achieve complete angiographic embolization. [ABSTRACT FROM AUTHOR]

Background Use of the radial artery as an access site for neurointerventional procedures is gaining popularity after several studies in interventional cardiology have demonstrated superior patient safety, decreased length of stay, and patient preference compared with femoral artery access. The transradial approach has yet to be characterized for intraoperative cerebral angiography. Objective To report a multicenter experience on the use of radial artery access in intraoperative cerebral angiography, including case series and discussion of technical nuances. Methods 27 patients underwent attempted transradial cerebral angiography between May 2017 and May 2019. Data were collected regarding technique, patient positioning, vessels selected, technical success rate, and access site complications. Results 24 of the 27 patients (88.8%) underwent successful transradial intraoperative cerebral angiography. 18 patients (66.7%) were positioned supine, 6 patients (22.2%) were positioned prone, 1 patient (3.7%) was positioned lateral, and 2 patients (7.4%) were positioned three-quarters prone. A total of 31 vessels were selected including 13 right carotid arteries (8 common, 1 external, 4 internal), 11 left carotid arteries (9 common and 2 internal), and 6 vertebral arteries (5 right and 1 left). Two patients (7.4%) required conversion to femoral access in order to complete the intraoperative angiogram (1 due to arterial vasospasm and 1 due to inadvertent venous catheterization). One procedure (3.7%) was aborted because of inability to obtain the appropriate fluoroscopic views due to patient positioning. No patient experienced stroke, arterial dissection, or access site complication. Conclusions Transradial intraoperative cerebral angiography is safe and feasible with potential for improved operating room workflow ergonomics, faster patient mobility in the postoperative period, and reduced costs. [ABSTRACT FROM AUTHOR]

Objectives To study the correlation between wall shear stress and endothelial cell expression in a patient-specific, three-dimensional (3D)-printed model of a cerebral aneurysm. Materials and methods A 3D-printed model of a cerebral aneurysm was created from a patient's angiogram. After populating the model with human endothelial cells, it was exposed to media under flow for 24 hours. Endothelial cell morphology was characterized in five regions of the 3D-printed model using confocal microscopy. Endothelial cells were then harvested from distinct regions of the 3D-printed model for mRNA collection and gene analysis via quantitative polymerase chain reaction (qPCR.) Cell morphology and mRNA measurement were correlated with computational fluid dynamics simulations. Results The model was successfully populated with endothelial cells, which survived under flow for 24 hours. Endothelial morphology showed alignment with flow in the proximal and distal parent vessel and aneurysm neck, but disorganization in the aneurysm dome. Genetic analysis of endothelial mRNA expression in the aneurysm dome and distal parent vessel was compared with the proximal parent vessels. ADAMTS-1 and NOS3 were downregulated in the aneurysm dome, while GJA4 was upregulated in the distal parent vessel. Disorganized morphology and decreased ADAMTS-1 and NOS3 expression correlated with areas of substantially lower wall shear stress and wall shear stress gradient in computational fluid dynamics simulations. Conclusions Creating 3D-printed models of patient-specific cerebral aneurysms populated with human endothelial cells is feasible. Analysis of these cells after exposure to flow demonstrates differences in both cell morphology and genetic expression, which correlate with areas of differential hemodynamic stress. [ABSTRACT FROM AUTHOR]

Background pediatric acute ischemic stroke with underlying large vessel occlusion is a rare disease with significant morbidity and mortality. there is a paucity of data about the safety and outcomes of endovascular thrombectomy in these cases, especially with modern devices. Methods We conducted a retrospective review of all pediatric stroke patients who underwent endovascular thrombectomy in nine US tertiary centers between 2008 and 2017. Tesults Nineteen patients (63.2% male) with a mean (SD) age of 10.9(6) years and weight 44.6 (30.8) kg were included. Mean (SD) NIH stroke scale (NIHSS) score at presentation was 13.9 (5.7). CT-based assessment was obtained in 88.2% of the patients and 58.8% of the patients had perfusionbased assessment. All procedures were performed via the transfemoral approach. The first-pass device was stentriever in 52.6% of cases and aspiration in 36.8%. successful revascularization was achieved in 89.5% of the patients after a mean (SD) of 2.2 (1.5) passes, with a mean (SD) groin puncture to recanalization time of 48.7 (37.3) min (median 41.5). The mean (SD) reduction in NIHss from admission to discharge was 10.2 (6.2). A good neurological outcome was achieved in 89.5% of the patients. one patient had post-revascularization seizure, but no other procedural complications or mortality occurred. Conclusions endovascular thrombectomy is safe and feasible in selected pediatric patients. Technical and neurological outcomes were comparable to adult literature with no safety concerns with the use of standard adult devices in patients as young as 18 months. This large series adds to the growing literature but further studies are warranted. [ABSTRACT FROM AUTHOR]

Background Cavernous carotid artery aneurysms (CCAs) represent a unique subset of intracranial aneurysms due to their distinct natural history and the anatomy of the cavernous sinus. enlarging CCAs can cause elastic compression of the parent internal carotid artery (ICA). We suggest defining aneurysms that cause luminal stenosis of their parent vessels as 'matricidal aneurysms.' Though many patients are asymptomatic, presenting symptoms of CCAs include ophthalmoplegia with resulting diplopia, vision changes, pain, ptosis, facial numbness, and cavernous-carotid fistula. Less commonly, patients with CCAs can present with epistaxis, subarachnoid hemorrhage, and--in cases of matricidal aneurysms--ischemia due to stenosis. The proper management of stenosis caused by a matricidal CCA is not well established and may not be intuitive. Methods We present a multicenter retrospective case series of patients with matricidal CCAs. Results Forty patients with matricidal aneurysms presented with both asymptomatic and symptomatic stenosis. These patients were either treated with conservative medical management, coiling, flow diversion, or endovascular sacrifice of the parent artery. Planned treatment modalities were not executed in 11 cases (28% treatment failure rate). Presenting symptoms, patient outcomes, and follow-up data are presented for all cases. Conclusion Matricidal aneurysms require careful consideration and planning. The restricted anatomy of the cavernous sinus can make successful execution of endovascular interventions more difficult. Direct elastic compression of the parent artery does not respond to angioplasty and stenting in the same way atherosclerotic stenosis does. Because of this, planning for the possibility of parent vessel sacrifice is important. [ABSTRACT FROM AUTHOR]

Background Dural venous sinus stenting has emerged as an effective and durable treatment for idiopathic intracranial hypertension (IIH). Improved visualization of the venous sinuses can improve stent placement. Methods We present two cases of IIH treated with venous sinus stenting in which retrograde three-dimensional rotational venography (3DRV) provided superior anatomical details of the venous sinuses for optimal sizing and positioning of stent. Results Comparison of pre-stent 3DRV with poststent contrast-enhanced flat panel detector CT allowed confirmation of stent placement and the result of stenosis dilation. Conclusion This 3DRV technique provides precise visualization of venous sinus stenosis prior to stenting without the need for arterial cerebral angiography during the treatment course. [ABSTRACT FROM AUTHOR]

Background Embolization before stereotactic radiosurgery (SRS) for brain arteriovenous malformations (BAVMs) is controversial. Objective To compare clinical and radiographic outcomes in patients undergoing pre-SRS embolization with ethylene copolymer (Onyx) with outcomes in patients undergoing SRS alone. Methods Seventy consecutive patients with BAVMs who underwent SRS were retrospectively reviewed. Univariate and multivariate analyses were performed to assess the factors associated with radiographic obliteration and complication. Results Forty-one (59%) patients presented without BAVM rupture and 29 (41%) patients presented with rupture. Pre-SRS embolization was used in 20 patients (28.6%; 7 unruptured and 13 ruptured). Twenty-five of 70 (36%) patients sustained a complication from treatment, including 6 (9%) patients with a post-SRS latency period hemorrhage. Ten (14%) patients had persistent neurological deficits after treatment. Functional outcome (as modified Rankin Scale), complication rate, and radiographic obliteration at last follow-up were not significantly different between embolized and non-embolized groups in both unruptured and ruptured BAVMs. For unruptured BAVMs, 3- and 5-year rates of radiographic obliteration were 23% and 73% for non-embolized patients and 20% and 60% for embolized patients, respectively. For ruptured BAVMs, 3- and 5-year rates of radiographic obliteration were 45% and 72% for non-embolized patients and 53% and 82% for embolized patients, respectively. Conclusion Pre-SRS embolization with Onyx was not associated with worse clinical or radiographic outcomes than SRS treatment without embolization. Pre-SRS embolization has a low complication rate and can safely be used to target high-risk BAVM features in carefully selected patients destined for SRS. [ABSTRACT FROM AUTHOR]

We report successful transvenous treatment of direct carotid–cavernous fistula in a patient with Ehlers–Danlos syndrome type IV using a novel triple-overlay embolization (TAILOREd) technique without the need for arterial puncture, which is known to be highly risky in this patient group. The TAILOREd technique allowed for successful treatment using preoperative MR angiography as a three-dimensional overlay roadmap combined with cone beam CT and live fluoroscopy, precluding the need for an arterial puncture. [ABSTRACT FROM AUTHOR]

Background Computational modeling of intracranial aneurysms provides insights into the influence of hemodynamics on aneurysm growth, rupture, and treatment outcome. Standard modeling of coiled aneurysms simplifies the complex geometry of the coil mass into a homogeneous porous medium that fills the aneurysmal sac. We compare hemodynamics of coiled aneurysms modeled from high-resolution imaging with those from the same aneurysms modeled following the standard technique, in an effort to characterize sources of error from the simplified model. Materials Physical models of two unruptured aneurysms were created using three-dimensional printing. The models were treated with coil embolization using the same coils as those used in actual patient treatment and then scanned by synchrotron X-ray microtomography to obtain high-resolution imaging of the coil mass. Computational modeling of each aneurysm was performed using patient-specific boundary conditions. The coils were modeled using the simplified porous medium or by incorporating the X-ray imaged coil surface, and the differences in hemodynamic variables were assessed. Results X-ray microtomographic imaging of coils and incorporation into computational models were successful for both aneurysms. Porous medium calculations of coiled aneurysm hemodynamics overestimated intraaneurysmal flow, underestimated oscillatory shear index and viscous dissipation, and over- or underpredicted wall shear stress (WSS) and WSS gradient compared with Xray- based coiled computational fluid dynamics models. Conclusions Computational modeling of coiled intracranial aneurysms using the porous medium approach may inaccurately estimate key hemodynamic variables compared with models incorporating highresolution synchrotron X-ray microtomographic imaging of complex aneurysm coil geometry. [ABSTRACT FROM AUTHOR]

Background Dural arteriovenous fistulae (dAVFs) comprise 10-15% of all intracranial arteriovenous malformations. The goal of surgical or endovascular intervention is complete obliteration of the fistulous connection(s). In cases where dAVF venous drainage is separate from normal cortical drainage, transvenous embolization can provide fast and effective fistula obliteration. Objective To describe a new method of efficient transvenous embolization (the 'dual microcatheter technique') for the treatment of dAVFs. Methods Three patients with dAVFs were treated using the dual microcatheter technique for transvenous embolization. Two microcatheters were placed in the distal aspect of the dAVF venous pouch, after which coil embolization reduced fistula flow, and liquid embolic agent injection with reflux into arterial feeders completed the obliteration of the fistula. Results Lesion grade ranged from Borden--Shucart grades 2 through 3. In all cases, dAVF venous drainage was isolated from the normal cerebral venous drainage. Dual microcatheter transvenous embolization was successful in all patients, with non-target embolization and no new postoperative deficits. At the last follow-up, all three patients were symptom-free without evidence of radiographic recurrence. Conclusions The dual microcatheter technique of transvenous dAVF embolization is safe and feasible in cases where dAVF venous outflow is isolated from normal cerebral venous drainage. [ABSTRACT FROM AUTHOR]

Background Venous sinus stenting is an effective treatment for patients with idiopathic intracranial hypertension (IIH) and venous sinus stenosis. Objective To determine the usefulness of venous sinus stenting in the treatment of patients with symptomatic venous sinus stenosis without a diagnosis of IIH. Methods We performed a retrospective review of a prospective multicenter database of patients undergoing venous sinus stenting between January 2008 and February 2016. Patients with acute dural venous sinus thrombosis, arteriovenous fistula or arteriovenous malformation, or IIH were excluded. Clinical, radiological, and ophthalmological information was recorded. Results Nine patients met the inclusion criteria and underwent venous sinus stenting for symptomatic dural venous sinus stenosis. Reasons for treatment included isolated unilateral pulsatile tinnitus (n=1), congenital hydrocephalus (n=2), unilateral pulsatile tinnitus following prior venous sinus thrombosis (n=1), acquired hydrocephalus following dural sinus thrombosis (n=2), meningitis (n=2) and tumor invasion into the dural venous sinus (n=1). Six patients underwent lumbar puncture or shunt tap, and all of these patients had elevated intracranial pressure. All stenoses were located in the transverse sinus, transverse--sigmoid junction and/ or jugular bulb, and all were treated with self-expanding bare-metal stents. At follow-up, clinical symptoms had resolved in all but two patients, both of whom had congenital hydrocephalus and pre-existing shunts. There was no significant in-stent stenosis, and patients with ophthalmological follow-up demonstrated improvement of papilledema. Conclusions Dural venous sinus stenting may be an effective treatment for patients with symptomatic venous sinus stenosis without IIH in carefully selected cases, but may not be effective in resolving the symptoms of congenital hydrocephalus. [ABSTRACT FROM AUTHOR]

Background and purpose Reported rates of in-stent restenosis after carotid artery stenting (CAS) vary, and restenosis risk factors are poorly understood. We evaluated restenosis rates and risk factors, and compared patients with 'hostile-neck' carotids (a history of ipsilateral neck surgery or irradiation) and atherosclerotic lesions. Methods Demographic, clinical, and radiological characteristics of patients undergoing cervical CAS between 1995 and 2010 with at least 1 month of follow-up were reviewed. Patients with substantial (≥50%) radiographic restenosis were compared with those without significant restenosis to identify restenosis risk factors. Results The analysis included 121 patients with 133 stented vessels; 91 (68.4%) lesions were symptomatic. Indications for stent placement included hostile-neck lesions, substantial surgical comorbidities, inclusion in a randomized carotid stenting trial, acute carotid occlusion, tandem stenosis, large pseudoaneurysm, high carotid bifurcation, and contralateral laryngeal nerve palsy. Procedures were technically successful in all but one lesion (99.2%). Perioperative stroke occurred in four cases (3.0%). Mean follow-up was 38 months (range 1-204 months), during which 23 vessels (17.3%) developed restenosis. Hostile-neck carotids (n=57) comprised 42.9% of all vessels treated and were responsible for 15 of 23 restenosis cases, resulting in a significantly higher restenosis rate than that of primary atherosclerotic lesions (26.3% vs 10.5%, p=0.017). By univariate analysis, the presence of calcified plaque was significantly associated with the incidence of in-stent restenosis (p=0.02). Conclusions Restenosis rates after carotid angioplasty and stenting are low. Patients with a history of ipsilateral neck surgery or irradiation are at higher risk for substantial radiographic and symptomatic restenosis. [ABSTRACT FROM AUTHOR]

Background Standard pretreatment with dual antiplatelet medication (DAPM) was compared with a standalone intraprocedural abciximab bolus for the prevention of thromboembolic and hemorrhagic events during endovascular stenting of unruptured intracrania aneurysms. Materials and methods We treated 94 patients with 99 aneurysms with intracranial stenting (with or without coiling). Patients were either pretreated with DAPM daily for ≥3 days before stenting (pretreatment group) or received an abciximab bolus during or immediately after stent placement followed by postoperative DAPM (abciximab group), at the treating physician's discretion. Twenty patients underwent immediate postoperative MRI. Demographic, clinical, and radiological information and periprocedural complications were recorded. Results There were 52 procedures in the pretreatment group and 47 in the abciximab group. More flow-diverting stents were placed in the pretreatment group than in the abciximab group (45 vs 23, p<0.001), and the aneurysm diameter was larger (11.2±6.7 vs 8.3 ±4.7 mm, p=0.01). There were 11 thrombotic and 7 access site complications, with no significant difference between the groups (p>0.99 and p=0.12, respectively). There were no intracranial hemorrhages. In patients with postoperative MRI, there was no difference in the presence of diffusion-restricted lesions between groups (p=0.20). Multivariate analysis of a composite of any complication did not show significant associations with aneurysm or patient variables in either group. Conclusions Standalone intraprocedural abciximab bolus was not associated with an increased rate of complications compared with pretreatment with DAPM for unruptured intracranial aneurysm stenting. [ABSTRACT FROM AUTHOR]

Purpose Fluoroscopic systems in modern interventional suites have the ability to perform flat panel detector CT (FDCT) with navigational guidance. Fusion with MR allows navigational guidance towards FDCT occult targets. We aim to evaluate the accuracy of this system using single-pass needle placement in a deep brain stimulation (DBS) phantom. Materials and methods MR was performed on a head phantom with DBS lead targets. The head phantom was placed into fixation and FDCT was performed. FDCT and MR datasets were automatically fused using the integrated guidance system (iGuide, Siemens). A DBS target was selected on the MR dataset. A 10 cm, 19 G needle was advanced by hand in a single pass using laser crosshair guidance. Radial error was visually assessed against measurement markers on the target and by a second FDCT. Ten needles were placed using CT-MR fusion and 10 needles were placed without MR fusion, with targeting based solely on FDCT and fusion steps repeated for every pass. Results Mean radial error was 2.75±1.39 mm as defined by visual assessment to the centre of the DBS target and 2.80±1.43 mm as defined by FDCT to the centre of the selected target point. There were no statistically significant differences in error between MR fusion and non-MR guided series. Conclusions Single pass needle placement in a DBS phantom using FDCT guidance is associated with a radial error of approximately 2.5-3.0 mm at a depth of approximately 80 mm. This system could accurately target sub-centimetre intracranial lesions defined on MR. [ABSTRACT FROM AUTHOR]