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Introduction Spinal dural arteriovenous fistulae (dAVFs) are uncommon lesions that often present with slowly progressive myelopathy. These shunts are located most commonly in the thoracolumbar region. A location in the cervical spine is considered exceedingly rare and has been reported most often in the context of subarachnoid hemorrhage. We report a series of five cases of upper cervical dAVFs and describe the clinical and angiographic characteristics of these lesions. Materials and methods A review of interventional neuroradiology database identified five patients with upper cervical dural arteriovenous fistulae (CdAVFs). We performed a review of the patient charts, imaging studies, including digital subtraction angiography (DSA) and C arm CTs (when available), and the operative records. The imaging studies were reviewed by two neuroradiologists with experience in spinal angiography and interventions. We also performed a detailed review of the English literature on this entity. Results Mean age of the patients was 61.6 years (range 45–75 years). There were three men and two women. Four of the five patients presented with subarachnoid hemorrhage (SAH) that could be attributed to the CdAVF. One patient had an incidental detection of the CdAVF while undergoing cerebral angiography for a ruptured left posterior communicating aneurysm. The fistulae were located at C1 or C2 level and supplied by C1/C2 radicular arteries. Small branches of anterior or lateral spinal artery were noted to supply the fistulae in four of the five patients. Embolization was performed in 3/5 lesions and was curative in one. Reduction in flow was accomplished in 2/5 but definitive cure using endovascular therapy was not possible due to small size of the feeder vessels and/or supply from ASA. One of these two patients has had microsurgical obliteration of the fistula. Two patients are being medically observed, one with incidentally detected fistula and another who refused microsurgical therapy. Conclusion Upper cervical dAVFs may possibly be an under recognized entity. Approximately half of the reported cases have presented with SAH. Endovascular therapy is often difficult due to small size, eloquent nature and multiplicity of feeder vessels. Microsurgical therapy is also difficult but may offer a chance of complete obliteration in selected cases. In high risk cases, expectant management may be reasonable since the clinical course from the hemorrhage seems to be fairly benign and significant complications from SAH are uncommon. We advocate bilateral selective vertebral angiography (in addition to usual DSA workup) with the inclusion of their cervical segments in evaluation of any patient with hemorrhage in the region of the foramen magnum/upper cervical spine. These lesions have a higher chance of detection if the upper cervical spine is included in the imaging field of view. [ABSTRACT FROM PUBLISHER]

Introduction Intracranial dural arteriovenous fistulas (dAVFs) are comprised of pathologic, dural based shunts and account for 10–15% of all intracranial arteriovenous malformations. These lesions have complex anatomy that is best studied with conventional digital subtraction angiography (DSA). Conventional DSA is however limited by its planar imaging nature. A more detailed analysis of these lesions is now possible with cone beam CT. We present our initial experience with 10 patients of dAVFs studied with C arm CT. Methods This study includes 10 patients with intracranial and skull base dAVFs that were evaluated with conventional DSA and a C arm CT (Dyna CT) between January 2009 and February 2010 by one of the authors (DG). The DSA evaluation included selected catheter angiograms of bilateral common, internal, external carotid and vertebral arteries. Additional Dyna CT evaluation was accomplished while injecting diluted contrast into the dominant feeding artery. MPRs were performed by using an external postprocessing workstation (syngoXWorkplace; Siemens Medical Solutions) to produce section thickness of 0.2–0.5 mm. This study is a retrospective review of patient charts, imaging studies and DSA/C arm CT evaluations. Results C arm CT was successfully performed on all patients and provided excellent quality images. The anatomic understanding of the osteodural network, location of arteriovenous shunt and venous compartment was aided by Dyna CT and significantly added to the understanding of these lesions. In addition, there were additional findings noted on Dyna CT that had significant impact on management of four of 10 patients. The final management included endovascular treatment exclusively in 5/10, combination of embolization and surgery in 1/10 and embolization followed by gamma knife in 1/10. Three of 10 patients are being managed conservatively in view of Borden type 1 fistulae that were minimally symptomatic. Conclusion C arm CT is complementary to DSA in the evaluation of cranial and skull base dAVFs. In many patients, Dyna CT provides information that is difficult to obtain from conventional DSA. In our initial experience, Dyna CT had a significant impact in the management of these lesions. [ABSTRACT FROM PUBLISHER]

Introduction Dural type fistulas of the cavernous sinus are complex lesions; transvenous embolization is often favored but may be difficult to accomplish if there is thrombosis, stenosis or occlusion of the drainage pathways. Surgical access to the superior ophthalmic vein (SOV) is very helpful in case of difficult endovascular access to the cavernous sinus. However, it is associated with a small but additional risk. This includes inability to cannulate the SOV or treat the fistula and less commonly intraorbital hemorrhage. With the availability of newer, flexible, distal access guide catheters, these difficult to treat cases could possibly be treated using exclusively endovascular approach. Materials and methods During the past 2 years, eight patients with symptomatic cavernous sinus fistulae were endovascularly treated by one of the authors (DG). Three of the seven lesions were considered difficult to treat using transvenous access on account of thrombosis/occlusion of the inferior petrosal sinus and presence of unfavorable angle and/or severe stenosis at the junction of the SOV with the angular vein. One of three patients had a previous failed attempt at embolization using the angular/facial vein approach. Embolization was performed in all three patients using the middle temporal vein (2/3) or facial/angular vein (1/3), with flexible, distal access guide catheters. Results Successful catheterization of the SOV was facilitated using a combination of flexible distal access catheter (neuron or Merci distal access catheter) and a microcatheter. The flexible, guide catheters could be advanced very distally and just short of the junction of the angular vein and SOV (1/3) and supraorbital vein and SOV (2/3). This provided a stable platform and enhanced the microcatheter navigation into otherwise difficult to access SOVs. All lesions were successfully treated with this approach. Conclusion Distal access flexible guide catheters can be advanced across tortuous venous anatomy and can even reach just short of the SOV. This helps in providing a markedly stable platform and helps superselective microcatheterization of the SOV. With the help of these newer guide catheters, many of the difficult to treat carotid–cavernous fistulas could possibly be treated using an exclusive endovascular approach thereby avoiding the need for direct surgical exposure of the SOV. [ABSTRACT FROM PUBLISHER]

Purpose This study was designed to evaluate the feasibility, inter-observer agreement and accuracy of Syngo iGuide intraoperative navigation planning system for percutaneous spine interventions. Methods and materials This cadaveric study was performed according to our institution guidelines for cadaver work. Two fresh frozen cadaver (one for thoracic and one for lumbar levels) were used to test the utility of a recently launched, commercially available flat panel application from Siemens Medical Systems that provides intraoperative virtual guidance to a user predefined needle path and target. Using this system, a total of 18 needle passes (eight thoracic and 10 lumbar levels) were performed by two experienced interventional neuroradiologists (nine passes per operator, alternate side and levels) using a unilateral transpedicular approach from T5 to T12 vertebral bodies and a bipedicular approach from L1 to L5 vertebral bodies. Entry and target points were first selected on a C arm dynaCT image to determine a safe path for the needle. The needle path, target point and three-dimensional images were registered to live fluoroscopy during the procedure and were used to guide needle placement in real time. After satisfactory placement of the needle, strictly using the guiding system, post C arm dynaCT images were obtained for measurements. Results Needle placement data from eight thoracic and 10 lumbar vertebral levels (T5–T12; L1–L5) were available for review. Needles were safely placed at all levels with no breach of the central canal, lateral or medial wall of pedicle or that of the anterior cortex. The average distance from the center of the predefined target to needle tip was 2.94 mm (3.07 for thoracic, 2.83 mm for lumbar) with a range from 1.4 mm to 4.8 mm. The average distance from the center of the target to the nearest part of the needle trajectory was 0.93 mm (0.97 mm for thoracic, 0.88 mm for lumbar) with a range from 0.00 mm to 2.4 mm. There was no significant difference between the two operators. Conclusion Use of the Syngo iGuide Needle Guidance intraoperative navigation system is feasible for spinal interventions. The needle can be placed to the target with less than 3 mm error in cadaver study. This software allows reliable and accurate needle placement by providing real time intraoperative navigation. Further testing in live subjects is needed to establish patient safety. Preliminary work on live patients is underway at our institution and appears promising. [ABSTRACT FROM PUBLISHER]

Purpose Bioactive polyglycolic/polylactic acid coated matrix detachable coils (Boston Scientific, Natick, Massachusetts, USA) were reported to incite intra-aneurysmal inflammation and fibrosis. Multiple large case series have shown no significant advantage with respect to aneurysm recurrence. Second generation Matrix2 coils were designed with improved platinum coil support and reduced bioactive copolymer friction. We assessed the safety and efficacy of Matrix2 coils in preventing aneurysm recanalization. Materials and methods 84 aneurysms were embolized using primarily Matrix2 coils (64 aneurysms with >90% Matrix2 coils). We studied patient demographics, aneurysm characteristics, embolization procedures, packing density, complications, postprocedure and follow-up angiographic/clinical outcomes. Anatomic results were evaluated using a modified 3 point Raymond scale (complete occlusion, neck remnant and residual aneurysm) with progressive occlusion or recanalization/recurrence strictly defined as any interval change in intra-aneurysmal opacification on both mid term and long term follow-up angiography. Results Mid term (mean 8.9±3.4 months) and long term (23.0±7.4 months) follow-up was available for 65 aneurysms. At mid term, 55 (85%) aneurysms remained stable or progressed to occlusion versus 10 (15%) recurrent aneurysms, seven (11%) requiring retreatment. At long term, 49 (75%) aneurysms remained stable or progressed to occlusion versus 16 (25%) recurrent aneurysms, 12 (18%) requiring retreatment. Recanalization occurred in 6/12 (50%) residual aneurysms as opposed to 10/53 (19%) completely occluded or neck remnant aneurysms. The recanalization rates of small (14%) versus large (71%) aneurysms was statistically significant with a differential coil packing density observed in recurrent (21%) versus stable/progressively occluded (28%) aneurysms (p<0.05). Statistical trends of recurrence were noted for ruptured aneurysms and wide necked (>4 mm) aneurysms. Four (5%) periprocedural complications were encountered with thromboembolic events related to coil mass or stent placement with three patients requiring thrombolysis and three developing neurological complications. Aneurysm rerupture occurred in one patient at 2 months postprocedure. Five patients expired from subarachnoid hemorrhage complications unrelated to the procedure. The majority of patients improved or remained neurologically intact at baseline on mid term and long term follow-up. Conclusion In our single center experience with Matrix2 coils, safe coil embolization is achievable with few complications. Although aneurysm recurrence rates are lower with Matrix2 coils than previous reports on first generation Matrix or platinum coils on mid term evaluation, we observed no significant benefit in aneurysm recanalization/recurrence after long term follow-up. Small aneurysm volumes and coil packing density are required to complement any benefit of the bioactive polymer coating. We await results from the multicenter, prospective and randomized MAPS trial for greater statistical power. [ABSTRACT FROM PUBLISHER]

An abstract for the article "Temporary flow arrest for tracking and placing the compliant ballon catheter at the neck of a large or giant aneurysm: technique and initial results," by D. Gandhi, S. Ansan and N. Razack is presented.

An abstract for the article "Covered stent graft for carotid pseudoaneurysms," by S. Ansari, V. Gluncic, N. Chaudhary et al. is presented.

Background: The safety and efficacy of endovascular thrombectomy (EVT) for large vessel occlusion (LVO) strokes associated with infective endocarditis (IE) compared with medical management (MM) is unclear., Methods: In this nationwide analysis of hospitalizations in the United States, we assessed the outcomes of EVT versus medical management (MM) for patients with LVO and IE. Primary outcome was routine home discharge with self-care. Secondary outcomes include home discharge, in-hospital mortality, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). Propensity score matching (PSM) was performed to adjust for confounders. Additional multivariable adjustments were performed for doubly robust analyses., Results: 2574 patients were identified; 656 (25.5%) received EVT. After PSM, the rate of routine discharge was significantly higher for patients with EVT compared with MM (14.6% vs 8.5%, p=0.021), and patients with EVT had significantly higher rate of home discharge (34.5% vs 26.5%, p=0.041), lower rate of in-hospital death (14.8% vs 25.2%, p=0.002), and lower rate of ICH (15.8% vs 23.1%, p=0.039). EVT was not associated with a different rate of SAH compared with MM (11.2% vs 7.9%, p=0.17). These associations remained unchanged with additional multivariable adjustments., Conclusion: For patients with LVO stroke and IE, EVT was associated with significantly higher odds of favorable hospitalization outcomes and lower odds of ICH compared with MM., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Cerebral dural arteriovenous fistulas (dAVFs) are commonly treated with endovascular embolization, either through arterial or venous routes in single or multi-staged procedures. Treatment outcomes depend on multiple factors, including the patient's clinical status, the anatomy of the malformation, and the operator's experience, but technical success is also highly dependent on choice of neurovascular devices and embolic agents. When transvenous routes are not feasible and the most obvious transarterial routes do not appear safe, deep knowledge of the dynamic fluid properties of liquid embolics can be a valuable asset. We present a case(video 1) in which a complex skull-base dAVF was completely occluded through a non-visualized previously partially embolized arterial feeder. It is a unique case in which the embolization takes advantage of the peculiar fluid dynamic properties of non-adhesive embolic agents (Onyx-Medtronic, Minnesota, USA) 18 and 34.1-3 neurintsurg;16/8/852/V1F1V1Video 1 Technical video presenting a dAVF completely cured through a non-visible previously embolized arterial pedicle., Competing Interests: Competing interests: DG reports grants from Microvention, the focused Ultrasound Foundation, the NIH and University Calgary/NoNo Therapeutics., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke (AIS) patients with large vessel occlusion (LVO). The SOFAST study collected clinical evidence on the safety and efficacy of the 6 French SOFIA Flow Plus aspiration catheter (SOFIA 6F) when used as first-line treatment., Methods: This was a prospective, multicenter investigation to assess the safety and efficacy of SOFIA 6F used for first-line aspiration. Anterior circulation LVO stroke patients were enrolled. The primary endpoint was the final modified Thrombolysis in Cerebral Infarction (mTICI)≥2b rate. Secondary endpoints included first-pass and first-line mTICI≥2b rates, times from arteriotomy to clot contact and mTICI≥2b, and 90-day modified Rankin Scale (mRS)≤2. First-line and final mTICI scores were adjudicated by an independent imaging core lab. Safety events were assessed by an independent clinical events adjudicator., Results: A total of 108 patients were enrolled across 12 centers from July 2020 to June 2022. Median age was 67 years, median National Institutes of Health Stroke Scale (NIHSS) was 15.5, and 56.5% of patients received intravenous thrombolytics. At the end of the procedure, 97.2%, 85.2%, and 55.6% of patients achieved mTICI≥2b, ≥2c, and 3, respectively. With SOFIA 6F first-line aspiration, 87.0%, 79.6%, and 52.8% achieved mTICI≥2b, ≥2c, and 3, respectively. After the first pass, 75.0%, 70.4%, and 50.9% achieved mTICI≥2b, ≥2c, and 3, respectively. Median times from arteriotomy to clot contact and successful revascularization were 12 and 17 min, respectively. At 90 days, 66.7% of patients achieved mRS≤2., Conclusions: First-line aspiration with SOFIA 6F is safe and effective with high revascularization rates and short procedure times., Competing Interests: Competing interests: DG: research funding from the National Institutes of Health, Focused Ultrasound Foundation, MicroVention, University of Calgary, and University of Maryland Medical Center; consultant for Navigantis. CS: research support from MicroVention, National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS), Balt, Penumbra, Medtronic, Cerenovus, Route 92, MIVI, Stryker; consultant for Medtronic, Stryker, Balt, Werfen, Viz.ai, MicroVention; shareholder for Neurotechnology Investors, REIST. DHS: consultant for Medtronic, Stryker, and Kaneka; speaker for Medtronic; proctor for Medtronic; grant support from MicroVention; advisory board for Scientia and Vasorum; stockholder of Scientia and Vasorum. GT: consultant for Dynamed, Medtronic, and Penumbra. DF: consultant for Medtronic, Cerenovus, MicroVention, Penumbra, Stryker, Balt USA, MENTICE, Neurogami, RAPID. AI, RAPID Medical, Phenox Medical, Scientia Medical, Perfuze, Vesalio; proctor for Medtronic, MicroVention; research support from MicroVention, Penumbra, Stryker, Balt USA, Siemens; advisory board on Arsenal Medical, NVMed, Perfuze; stock holder in Neurogami, Arsenal Medical, Scientia Medical, NVMed, and Perfuze., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Large vessel recanalization (LVR) before endovascular therapy (EVT) for acute large vessel ischemic strokes is a poorly understood phenomenon. Better understanding of predictors for LVR is important for optimizing stroke triage and patient selection for bridging thrombolysis., Methods: In this retrospective cohort study, consecutive patients presenting to a comprehensive stroke center for EVT treatment were identified from 2018 to 2022. Demographic information, clinical characteristics, intravenous thrombolysis (IVT) use, and LVR before EVT were recorded. Factors independently associated with different rates of LVR were identified, and a prediction model for LVR was constructed., Results: 640 patients were identified. 57 (8.9%) patients had LVR before EVT. A minority (36.4%) of LVR patients had significant improvements in National Institutes of Health Stroke Scale. Independent predictors for LVR were identified and used to construct the 8-point HALT score: hyperlipidemia (1 point), atrial fibrillation (1 point), location of vascular occlusion (internal carotid: 0 points, M1: 1 point, M2: 2 points, vertebral/basilar: 3 points), and thrombolysis at least 1.5 hours before angiography (3 points). The HALT score had an area under the receiver-operating curve (AUC) of 0.85 (95% CI 0.81 to 0.90, P<0.001) for predicting LVR. LVR before EVT occurred in only 1 of 302 patients (0.3%) with low (0-2) HALT scores., Conclusions: IVT at least 1.5 hours before angiography, site of vascular occlusion, atrial fibrillation, and hyperlipidemia are independent predictors for LVR. The 8-point HALT score proposed in this study may be a valuable tool for predicting LVR before EVT., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Elevated International Normalized Ratio (INR) is a marker of coagulopathy, but its impact on outcomes following mechanical thrombectomy (MT) in patients with stroke is unclear. This study investigates the impact of mild INR elevations on clinical outcomes following MT., Methods: In this retrospective cohort study, consecutive patients with stroke treated with MT were identified from 2015 to 2020 at a Comprehensive Stroke Center. Demographic information, past medical history, INR, National Institutes of Health Stroke Scale score, use of tissue plasminogen activator, and last known normal to arteriotomy time were recorded. Outcome measures included modified Thrombolysis in Cerebral Infarction (mTICI) score, modified Rankin Scale (mRS) score at 90 days, and intracerebral hemorrhage (ICH). Patients were divided into two groups: normal INR (0.8-1.1) and mildly elevated INR (1.2-1.7)., Results: A total of 489 patients were included for analysis, of which 349 had normal INR and 140 had mildly elevated INR. After multivariable adjustments, mildly elevated INR was associated with lower odds of excellent outcomes (mRS 0-1, OR 0.24, p=0.009), lower odds of functional independence (mRS 0-2, OR 0.38, p=0.038), and higher odds of 90-day mortality (OR 3.45, p=0.018). Elevated INR was not associated with a higher likelihood of ICH, and there were no differences in rates of HI1, HI2, PH1, or PH2 hemorrhagic transformations; however, elevated INR was associated with significantly higher odds of 90-day mortality in patients with ICH (OR 6.22, p=0.024). This effect size was larger than in patients without ICH (OR 3.38, p<0.001)., Conclusion: In patients with stroke treated with MT, mildly elevated INR is associated with worse clinical outcomes after recanalization and may worsen the mortality risk of hemorrhagic transformations., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: High levels of platelet inhibition have been associated with hemorrhagic complications following Pipeline embolization of intracranial aneurysms. We therefore titrate clopidogrel dosing to maintain a moderate level of platelet inhibition using the VerifyNow P2Y12 assay. However, many patients demonstrate dramatic increases in platelet inhibition following treatment despite being on a consistent antiplatelet regimen. We therefore elected to explore the incidence of this phenomenon and possible predisposing factors., Methods: All successful Pipeline aneurysm treatments performed at our institution from 2011 to 2019 with moderate procedure-day platelet inhibition levels as indicated by a VerifyNow PRU of 60-235 were included. Patients who received glycoprotein IIb/IIIa inhibitors and those treated for ruptured/symptomatic lesions were excluded. The incidence of excessive platelet inhibition defined by a PRU<60 within 8 weeks of treatment was noted. Multivariable logistic regression was performed to determined independent predictors of the phenomenon., Results: Some 190 treatments were performed in 178 qualifying patients. A post-procedure PRU <60 occurred following 79% of treatments, documented on average after 8.5 (range 1-47) days. A higher procedure day hematocrit level (P=0.003, OR 1.09, 95% CI 1.029 to 1.152) was an independent predictor of reaching a PRU <60, while intra-procedural midazolam exposure (P=0.044, OR 0.44, 95% CI 0.201 to 0.980) and a higher procedure-day PRU (P=0.047, OR 0.99, 95% CI 0.982 to 1.000) were associated with a reduced odds. Time-since-procedure and hematocrit levels were associated with excessive platelet inhibition when excluding patients who initially demonstrated hyperresponse., Conclusion: Elevations in platelet inhibition were frequently observed following flow diversion with Pipeline., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

An adult patient with acute basilar artery occlusion underwent mechanical thrombectomy. After complete reperfusion, a 70% residual stenosis of the proximal basilar artery was observed. Intravascular optical coherence tomography (OCT) identified lipid plaques with an intact fibrous cap and thrombus in the culprit lesion, indicating plaque erosion was the mechanism of in situ thrombosis. Adjunctive antiplatelet therapy rather than rescue interventions was pursued for its beneficial effects in acute coronary syndrome caused by plaque erosion. The patient had a 90-day modified Rankin Scale score of 0. OCT enables precise evaluation of vessel characteristics following thrombectomy, so may improve outcomes through subsequent tailored treatments., Competing Interests: Competing interests: SL received research funding support from National Natural Science Foundation of China. SL and TT received research funding support from Central Committee Healthcare Project and Emergency Project of Beijing Shijitan Hospital. PW is secretary of the Society for Image-Guided Neurointerventions (SIGN), and holds equity in Ti-com, LLC and Intra-Art, LLC. DG received research grants from Focused Ultrasound Foundation, INSIGHTEC and MicroVention., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: To evaluate the cost-effectiveness of endovascular thrombectomy (EVT) to treat large vessel occlusion (LVO) in patients with acute, minor stroke (National Institute of Health Stroke Scale (NIHSS) <6) and impact of occlusion site., Methods: A Markov decision-analytic model was constructed accounting for both costs and outcomes from a societal perspective. Two different management strategies were evaluated: EVT and medical management. Base case analysis was done for three different sites of occlusion: proximal M1, distal M1 and M2 occlusions. One-way, two-way and probabilistic sensitivity analyses were performed., Results: Base-case calculation showed EVT to be the dominant strategy in 65-year-old patients with proximal M1 occlusion and NIHSS <6, with lower cost (US$37 229 per patient) and higher effectiveness (1.47 quality-adjusted life years (QALYs)), equivalent to 537 days in perfect health or 603 days in modified Rankin score (mRS) 0-2 health state. EVT is the cost-effective strategy in 92.7% of iterations for patients with proximal M1 occlusion using a willingness-to-pay threshold of US$100 000/QALY. EVT was cost-effective if it had better outcomes in 2%-3% more patients than intravenous thrombolysis (IVT) in absolute numbers (base case difference -16%). EVT was cost-effective when the proportion of M2 occlusions was less than 37.1%., Conclusions: EVT is cost-effective in patients with minor stroke and LVO in the long term (lifetime horizon), considering the poor outcomes and significant disability associated with non-reperfusion. Our study emphasizes the need for caution in interpreting previous observational studies which concluded similar results in EVT versus medical management in patients with minor stroke due to a high proportion of patients with M2 occlusions in the two strategies., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The utility of using the VerifyNow P2Y12 platelet inhibition assay in patients undergoing Pipeline embolization of intracranial aneurysms remains controversial. As we have routinely employed the assay for patients undergoing flow diversion, we elected to explore the relationship between P2Y12 hyporesponse as indicated by a P2Y12 Reaction Units (PRU) value >200 and treatment outcomes, including intraprocedural platelet aggregation and ischemic complications., Methods: All successful intracranial aneurysm Pipeline treatments performed at our institution from November 2011 to May 2019 were included. The rate of P2Y12 hyporesponse and treatment outcomes were evaluated. Multivariable logistic regression was utilized to determine independent predictors of treatment outcomes., Results: 333 qualifying treatments were performed in 297 patients. Clopidogrel hyporesponse was initially noted in 24%, falling to 17% by day-of-procedure by dose titration. A glycoprotein (GP) IIb/IIIa inhibitor was administered prophylactically in 3% of cases for persistent, profound hyporesponse. 27 (8.1%) patients developed acute platelet aggregation; only 6 demonstrated day-of-procedure P2Y12 hyporesponse. Day-of-procedure hyporesponse was not associated with intraprocedural platelet aggregation or ischemic complications. Greater Pipeline embolization device (PED) diameter was associated with a reduced odds of platelet aggregation (OR 0.38, 95% CI 0.17 to 0.85; p=0.019). Antiplatelet non-compliance (OR 25.20, 95% CI 3.86 to 164.61; p=0.001) and treatment of posterior circulation aneurysms (OR 5.23, 95% CI 1.22 to 22.33; p=0.026) were the only independent predictors of ischemic complications., Conclusions: P2Y12 hyporesponse was not associated with acute platelet aggregation or ischemic complications in our patients undergoing Pipeline embolization of intracranial aneurysms, possibly due to aggressive management of the hyporesponse using clopidogrel dose titration and/or GP IIb/IIIa inhibitor administration., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The cost-effectiveness of endovascular thrombectomy (EVT) in patients with acute ischemic stroke due to M2 branch occlusion remains uncertain., Objective: To evaluate the cost-effectiveness of EVT compared with medical management in patients with acute stroke presenting with M2 occlusion using a decision-analytic model., Methods: A decision-analytic study was performed with Markov modeling to estimate the lifetime quality-adjusted life years and associated costs of EVT-treated patients compared with no-EVT/medical management. The study was performed over a lifetime horizon with a societal perspective in the Unites States setting. Base case, one-way, two-way, and probabilistic sensitivity analyses were performed., Results: EVT was the long-term cost-effective strategy in 93.37% of the iterations in the probabilistic sensitivity analysis, and resulted in difference in health benefit of 1.66 QALYs in the 65-year-old age groups, equivalent to 606 days in perfect health. Varying the outcomes after both strategies shows that EVT was more cost-effective when the probability of good outcome after EVT was only 4-6% higher relative to medical management in clinically likely scenarios. EVT remained cost-effective even when its cost exceeded US$200 000 (threshold was US$209 111). EVT was even more cost-effective for 55-year-olds than for 65-year-old patients., Conclusion: Our study suggests that EVT is cost-effective for treatment of acute M2 branch occlusions. Faster and improved reperfusion techniques would increase the relative cost-effectiveness of EVT even further in these patients., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The benefit of endovascular thrombectomy (EVT) in stroke patients with large-vessel occlusion (LVO) depends on the degree of recanalization achieved. We aimed to determine the health outcomes and cost implications of achieving TICI 2b vs TICI 3 reperfusion in acute stroke patients with LVO., Methods: A decision-analytic study was performed with Markov modeling to estimate the lifetime quality-adjusted life years (QALY) of EVT-treated patients, and costs based on the degree of reperfusion achieved. The study was performed with a societal perspective in the United States' setting. The base case calculations were performed in three age groups: 55-, 65-, and 75-year-old patients., Results: Within 90 days, achieving TICI 3 resulted in a cost saving of $3676 per patient and health benefit of 11 days in perfect health as compared with TICI 2b. In the long term, for the three age groups, achieving TICI 3 resulted in cost savings of $46,498, $25,832, and $15 719 respectively, and health benefits of 2.14 QALYs, 1.71 QALYs, and 1.23 QALYs. Every 1% increase in TICI 3 in 55-year-old patients nationwide resulted in a cost saving of $3.4 million and a health benefit of 156 QALYs. Among 65-year-old patients, the corresponding cost savings and health benefit were $1.9 million and 125 QALYs., Conclusion: There are substantial cost and health implications in achieving complete vs incomplete reperfusion after EVT. Our study provides a framework to assess the cost-benefit analysis of emerging diagnostic and therapeutic techniques that might improve patient selection, and increase the chances of achieving complete reperfusion., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The first pass effect has been recently reported as a predictor of good clinical outcome after stroke thrombectomy. We evaluate the first pass effect on outcome and the influence of revascularization in these and other patients., Methods: We performed a retrospective analysis of a prospectively maintained database on anterior cerebral circulation stroke thrombectomy cases from April 2012 to April 2018. Data compiled included patient demographics, presenting National Institutes of Health Stroke Scale score, vessel occlusion site, thrombectomy procedural details, and 90 day modified Rankin Scale scores., Results: 205 patients were included. The numbers of patients who underwent one, two, three, four, five, and six passes were 69, 70, 55, 9, 1, and 1, respectively. Successful revascularization was achieved in 87%, 83%, and 64% of patients in the one, two, and 3 or more passes groups, respectively (p=0.002). Good functional outcome was inversely correlated with number of passes when comparing the one, two, and three or more passes groups (54%, 43%, 29%; P=0.014). In patients with full revascularization, there was no significant difference in good functional outcomes between the one, two, and three or more passes groups (64%, 65%, 50%; P=0.432). Number of passes was not an independent negative predictor of good clinical outcome (OR 1.66, 95% CI 0.82 to 3.39; P=0.165)., Conclusions: First pass thrombectomy patients have better functional outcomes compared with beyond-first pass patients. This effect is related at least in part to a higher rate of revascularization in one pass patients. Revascularization beyond the first pass should continue to be the goal of stroke thrombectomy., Competing Interests: Competing interests: GJ has research grant funding from Stryker Neurovascular and Microvention not directly related to the work presented here., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Flow diversion using the Pipeline embolization device (PED) has become a widely used treatment method for intracranial aneurysms. However, a subset of aneurysms will fail to occlude following treatment and the factors that influence the efficacy of flow diversion remain uncertain. As smaller diameter PEDs inherently have greater metal density than larger devices, we elected to investigate whether PED diameter influences treatment efficacy when using a single device. We also evaluated other factors that may influence treatment outcomes with PED., Methods: We retrospectively evaluated all patients treated for an intracranial saccular aneurysm at our institution with a single PED at least 12 months prior to the time of data collection. Patients treated with multiple devices, adjunctive coiling, traumatic and fusiform target aneurysms, as well as patients with inadequate imaging follow-up (<12 months) were excluded., Results: 158 aneurysms in 124 patients (128 treatments) met the inclusion criteria for our study. 123 aneurysms (80%) were occluded over an average follow-up of 26.6 months. Multivariable logistic regression showed that branch vessel incorporation into the target aneurysm sac (p<0.001, OR=0.15) was significantly associated with aneurysm persistence, while smaller PED diameter was significantly associated with aneurysm occlusion (p=0.008; OR=0.30)., Conclusions: PED diameter significantly impacts outcomes when using a single device for the treatment of small anterior circulation intracranial saccular aneurysms, most likely due to the inherent greater metal density of smaller devices. This factor should be taken into account when planning endovascular aneurysm treatment with PED., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Objective: Acute thrombus formation following aneurysm treatment with the Pipeline embolization device (PED) is a potentially devastating complication that may result in significant thromboembolic sequelae if not promptly treated. We therefore evaluated PED cases complicated by acute thrombus formation at our institution, with an emphasis on identifying early angiographic signs that may portend this event., Materials and Methods: We retrospectively identified cases of acute thrombosis following PED placement in 100 consecutive procedures performed at our institution from a prospectively maintained clinical database. Angiographic findings were analyzed for early signs of acute thrombus formation. We also evaluated the efficacy of treatment of this complication with a glycoprotein IIb/IIIa inhibitor (abciximab), as well as the results of pre-procedure platelet inhibition testing., Results: Acute thrombus formation was encountered in five patients following PED placement (5%). Early angiographic signs were present in all cases and included progressive stagnation of blood flow in covered side branches, occlusion of covered side branches, excessive stagnation of blood flow in the target aneurysm, as well as occlusion of the target aneurysm. These sequelae completely resolved following abciximab treatment in all five cases, with no permanent neurological morbidity or mortality. Four of the five patients had a pre-procedure P2Y12 value >200 (range 201-227)., Conclusions: Progressive stagnation or occlusion of covered side branches or target aneurysm are early angiographic signs of acute thrombus formation following PED placement and should prompt immediate treatment with a glycoprotein IIb/IIIa inhibitor. Platelet inhibition testing may help identify those patients who are at an increased risk for this complication., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: New device technology has changed the techniques used for revascularization of emergent large vessel occlusion in acute stroke. We report technical results using stent retrievers (SRs) for thrombectomy alone versus SRs used in conjunction with a new group of devices, intracranial aspiration catheters (IACs). Our aim is to demonstrate differences in procedural time and thrombectomy attempts between these two groups., Methods: A retrospective evaluation was performed of a prospectively maintained database of 97 patients treated at a single institution for anterior circulation stroke with SRs. Patients were divided into two groups, a combination group defined as the SR/IAC group and the SR alone group defined as the SR group., Results: Patients in the SR/IAC group had a mean age of 66 years vs 59 years in the SR group (p=0.008). Mean presenting National Institutes of Health Stroke Scale (NIHSS) scores in the SR/IAC and control groups were 18.7 and 18.2, respectively (p=0.50). Recanalization rates (Thrombolysis In Cerebral Infarction (TICI) 2b or 3) in the SR/IAC and SR groups were 85% (58/68) and 90% (26/29), respectively (p=0.41). Mean time from groin arteriotomy to recanalization was 50±3.6 min (range 19-136) in the SR/IAC group (n=59) and 61±6.6 min (range 28-140) in the SR group (n=27) (p=0.049). The total number of thrombectomy attempts in the SR/IAC and SR groups were 1.9±0.1 (range 1-4) and 2.5±0.6 (range 1-6), respectively (p=0.009). Post-procedural subarachnoid hemorrhage was seen in 15% (10/68) and 10% (3/29) of cases in the SR/IAC and SR groups, respectively (p=0.41)., Conclusion: When using SRs for intracranial stroke thrombectomy, the concurrent use of IACs is associated with a decrease in procedural time and thrombectomy attempts compared with use of SRs alone., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: Flow diversion with the Pipeline embolization device is a well-established method of intracranial aneurysm treatment. However, deployment of the first-generation device (Pipeline Classic) can be technically challenging. The Pipeline Flex contains the same flow-diverting stent with a modified delivery system., Objective: To compare procedural outcomes between the first-generation device (Pipeline Classic) and the Pipeline Flex., Methods: Thirty-eight of the first 40 consecutive patients who underwent intracranial aneurysm treatment with the Pipeline Flex and 58 of the most recent 60 consecutive patients who underwent treatment with the Pipeline Classic at our institution were evaluated. Patient demographics, aneurysm characteristics, technical procedural details, and early outcomes were analyzed., Results: The two groups were comparable for age, gender, and location of target aneurysms. Use of Pipeline Flex decreased procedure time by 44.2 min (p≤0.001) and fluoroscopy time by 22.0 min (p=0.001) compared with the Pipeline Classic. Similarly, radiation exposure was less in the Flex group with a mean difference of 3473.5 Gy cm 2 (p=0.002), while contrast usage was decreased with a mean difference of 22.3 mL (p=0.007). These differences remained significant in multivariate regression analysis. Finally, the rate of device deployment failure was lower in the Flex group (7.1%) than in the Classic group (23.9%) (p=0.034)., Conclusions: Use of Pipeline Flex significantly reduces the total procedure and fluoroscopy time, contrast usage, patient radiation exposure, and proportion of recaptured devices in comparison with the Pipeline Classic, probably owing to an enhanced delivery system that allows for more reliable and controlled deployment., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Accurate and timely diagnosis of intracranial vasculopathies is important owing to the significant risk of morbidity with delayed and/or incorrect diagnosis both from the disease process and inappropriate therapies. Conventional luminal imaging techniques for analysis of intracranial vasculopathies are limited to evaluation of changes in the vessel lumen. Vessel wall MRI techniques can allow direct characterization of pathologic changes of the vessel wall. These techniques may improve diagnostic accuracy and improve patient outcomes. Extracranial carotid vessel wall imaging has been extensively investigated in patients with atherosclerotic disease and has been shown to accurately assess plaque composition and identify vulnerable plaque characteristics that may predict stroke risk beyond luminal stenosis alone. This review provides a brief history of vessel wall MRI, an overview of the intracranial vessel wall MRI techniques, its applications, and imaging findings of various intracranial vasculopathies pertinent to the neurointerventionalist, neurologist, and neuroradiologist. We searched MEDLINE, PubMed, and Google for English publications containing any of the following terms: 'intracranial vessel wall imaging', 'intracranial vessel wall', and 'intracranial vessel wall MRI'., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

This report describes two cases of post-traumatic, high flow carotid-cavernous fistulas that demonstrated residual shunting after initial embolization with coils and Onyx, and that were successfully closed with pipeline embolization devices. Following their combined endovascular treatments, the patients experienced clinical improvement of symptoms with durable obliteration of the fistulous communications., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Accurate and timely diagnosis of intracranial vasculopathies is important due to significant risk of morbidity with delayed and/or incorrect diagnosis both from the disease process as well as inappropriate therapies. Conventional vascular imaging techniques for analysis of intracranial vascular disease provide limited information since they only identify changes to the vessel lumen. New advanced MR intracranial vessel wall imaging (IVW) techniques can allow direct characterisation of the vessel wall. These techniques can advance diagnostic accuracy and may potentially improve patient outcomes by better guided treatment decisions in comparison to previously available invasive and non-invasive techniques. While neuroradiological expertise is invaluable in accurate examination interpretation, clinician familiarity with the application and findings of the various vasculopathies on IVW can help guide diagnostic and therapeutic decision-making. This review article provides a brief overview of the technical aspects of IVW and discusses the IVW findings of various intracranial vasculopathies, differentiating characteristics and indications for when this technique can be beneficial in patient management., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: Deconstructive approaches may be necessary to treat a variety of neurovascular pathologies. Recently, a new device has become available for endovascular arterial occlusion that may have unique applications in neurovascular disease. The Micro Vascular Plug (MVP, Reverse Medical, Irvine, California, USA) has been designed for vessel occlusion through targeted embolization., Purpose: To report the results from our initial experience with eight consecutive patients in whom the MVP was used to achieve endovascular occlusion of an artery in the head and neck., Methods: Eight consecutive patients treated over a nine-month period were included. The patients' radiographic and electronic medical records were retrospectively reviewed. Specifically demographic information, clinical indication, site of arterial occlusion, size of MVP, time to vessel occlusion, clinical complications, use of other secondary embolic agents, and clinical outcome were recorded. Follow-up information when available is presented., Results: The MVP was used in eight patients for the treatment of neurovascular disease. Indications for treatment included post-traumatic head/neck bleeding (n=3), carotid-cavernous fistula (1), vertebral-vertebral fistula (1), giant fusiform vertebral aneurysm (1), stump-emboli after carotid dissection (1), and iatrogenic vertebral artery penetrating injury (1). One device was used in five patients, two in two patients, and one patient with extensive vertebral-vertebral venous fistula required three plugs to effectively trap the fistula from proximal and distal aspects. Vessel occlusion was obtained in <2 min in each case and there were no procedural complications. Four patients were followed up and no incidence of plug migration or vessel recanalization was seen., Conclusions: To the best of our knowledge, this is the first series reporting the use of MVP in neurovascular disease. Use of this device may be associated with shorter procedural times and cost savings in comparison with the use of microcoils for vessel occlusion. Our experience shows that MVP can have unique applications in neurovascular pathologies and it complements other occlusive devices., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Flow diversion is a promising technique for cerebral aneurysm treatment but presents new and sometimes unique challenges. Transient reversible narrowing due to device reconfiguration of the pipeline embolization device (PED) has not been previously described. Here we describe a patient with dolichoectasia of the distal right internal carotid artery with an associated saccular sidewall aneurysm who developed asymptomatic circumferential narrowing of the proximal aspect of the PED in the first month following deployment. The patient was followed conservatively and demonstrated partial resolution of device narrowing on 6 month follow-up imaging., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Although usually asymptomatic, a persistent trigeminal artery (PTA) can rarely be associated with a direct fistula to the cavernous sinus (ie, trigemino-cavernous fistula). We present three patients with trigemino-cavernous fistulas; two were subsequently treated using modern endovascular techniques while the third initially declined therapy. We then review the literature of reported cases of this unusual entity. The aberrant anatomy associated with a PTA presents unique challenges to the management of these lesions, and must be well delineated prior to treatment. Finally, conservative management of trigemino-cavernous fistulas, either de novo or recurrent, may be considered if they demonstrate no evidence of cortical venous reflux and patient symptoms are tolerable., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

A 22-year-old woman was involved in a motor vehicle collision resulting in multiple facial fractures and extensive internal carotid artery (ICA) injury including a right carotid-cavernous fistula, complex dissection flap and dissecting aneurysms. Endovascular coil embolization was initially performed to treat the cavernous carotid fistula and then again on two separate occasions to treat expanding dissecting aneurysms. Parent vessel reconstruction of the right ICA was subsequently performed with the Pipeline embolization device, resulting in complete anatomical restoration of this vessel., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background and Purpose: Technological advances have helped to improve the efficiency of treating patients with large vessel occlusion in acute ischemic stroke. Unfortunately, the sequence of events prior to reperfusion may lead to significant treatment delays. This study sought to determine if high-volume (HV) centers were efficient at delivery of endovascular treatment approaches., Methods: A retrospective review was performed of nine centers to assess a series of time points from obtaining a CT scan to the end of the endovascular procedure. Demographic, radiographic and angiographic variables were assessed by multivariate analysis to determine if HV centers were more efficient at delivery of care., Results: A total of 442 consecutive patients of mean age 66 ± 14 years and median NIH Stroke Scale score of 18 were studied. HV centers were more likely to treat patients after intravenous administration of tissue plasminogen activator and those transferred from outside hospitals. After adjusting for appropriate variables, HV centers had significantly lower times from CT acquisition to groin puncture (OR 0.991, 95% CI 0.989 to 0.997, p=0.001) and total procedure times (OR 0.991, 95% CI 0.986 to 0.996, p=0.001). Additionally, patients treated at HV centers were more likely to have a good clinical outcome (OR 1.86, 95% CI 1.11 to 3.10, p<0.018) and successful reperfusion (OR 1.82, 95% CI 1.16 to 2.86, p<0.008)., Conclusions: Significant delays occur in treating patients with endovascular therapy in acute ischemic stroke, offering opportunities for improvements in systems of care. Ongoing prospective clinical trials can help to assess if HV centers are achieving better clinical outcomes and higher reperfusion rates.

Purpose: Advanced neuroimaging techniques may improve patient selection for endovascular stroke treatment but may also delay time to reperfusion. We studied the effect of advanced modality imaging with CT perfusion (CTP) or MRI compared with non-contrast CT (NCT) in a multicenter cohort., Materials and Methods: This is a retrospective study of 10 stroke centers who select patients for endovascular treatment using institutional protocols. Approval was obtained from each institution's review board as only de-identified information was used. We collected demographic and radiographic data, selected time intervals, and outcome data. ANOVA was used to compare the groups (NCT vs CTP vs MRI). Binary logistic regression analysis was performed to determine factors associated with a good clinical outcome., Results: 556 patients were analyzed. Mean age was 66 ± 15 years and median National Institutes of Health Stroke Scale score was 18 (IQR 14-22). NCT was used in 286 (51%) patients, CTP in 190 (34%) patients, and MRI in 80 (14%) patients. NCT patients had significantly lower median times to groin puncture (61 min, IQR (40-117)) compared with CTP (114 min, IQR (81-152)) or MRI (124 min, IQR (87-165)). There were no differences in clinical outcomes, hemorrhage rates, or final infarct volumes among the groups., Conclusions: The current retrospective study shows that multimodal imaging may be associated with delays in treatment without reducing hemorrhage rates or improving clinical outcomes. This exploratory analysis suggests that prospective randomised studies are warranted to support the hypothesis that advanced modality imaging is superior to NCT in improving clinical outcomes.

Background: A combined imaging suite is useful in the diagnosis and treatment of vascular disease involving the head and neck. This study demonstrates the utility of a multidetector row CT and biplane digital subtraction angiography (DSA) system (hybrid suite) with a single interactive table for the evaluation and treatment of neurovascular disease., Methods: 30 patients were studied utilizing the hybrid suite. Direct intra-arterial and selective intravenous injection of contrast with CT imaging (IA-CTA and IV-CTV) was performed in nine vascular tumors, three intracranial arteriovenous malformations, four spinal vascular lesions, one aneurysm and two inferior petrosal sinus sampling cases. Angiography with CT perfusion (CTP) imaging was obtained in five temporary balloon occlusion tests, two ischemic stroke and two vasospasm cases. A CT scan of the head was obtained in two cases during aneurysm coiling. The value of the IA-CTA and IV-CTV images compared with conventional CT and MRI images was qualitatively assessed., Results: All studies were technically successful with no complications. IA-CTA and IV-CTV were useful in the diagnosis and treatment of vascular disease. All IA-CTA and IV-CTV images were qualitatively graded as superior to conventional imaging. CTP imaging provided information about the penumbra and area of infarction in five temporary balloon test occlusions, two ischemic stroke and two vasospasm cases. A CT scan of the head provided timely information in two aneurysm coiling cases. The hybrid suite allowed angiography and CT scanning to be performed immediately without patient transfer., Conclusion: This hybrid suite improves the diagnostic and therapeutic capabilities of treating a multitude of neurovascular diseases.

The case history is described of a patient referred to our institution with facial nerve palsy following embolization of a middle cranial fossa dural arteriovenous fistula using ethylene vinyl alcohol copolymer (EVOH). Facial nerve decompression was performed which showed evidence of extensive penetration of EVOH into the vasa nervosa of the facial nerve. Facial nerve palsy is a debilitating complication that can be avoided by attention to the lower cranial nerve arterial supply during careful procedural planning and consideration of alternative strategies for fistula obliteration in cases where eloquent feeders are involved.

Objective: To describe our experience with very distal placement of the Neuron 6 F 0.053 inch inner luminal diameter guide catheter (Penumbra Inc, San Leandro, California, USA) within the intracranial and extracranial vasculature to allow treatment of various neurovascular pathologies. Previously, this was thought to be only possible with a microcatheter., Methods: 12 cases are presented in which traditional guide catheters were unable to successfully navigate tortuous anatomy or provide stable support for intervention., Results: The Neuron 6 F 0.053 inch inner luminal diameter delivery catheter (Penumbra) was placed in a very distal location within the internal carotid artery, external carotid artery and venous system enabling successful endovascular treatment of the intracranial pathology with no related neurological complications., Conclusion: All lesions were successfully treated through a microcatheter advanced in a coaxial fashion through the distally placed guide catheter. There were no complications related to the distal position of the guide catheter.

Plasma mediated radiofrequency ablation (pmRFA) may allow for the percutaneous treatment of spinal tumors with a decreased risk of thermal injury to neural structures compared with traditional (radiofrequency or interstitial laser) ablation. However, usage of pmRFA has not been previously reported for a primary bone tumor, including an osteoid osteoma. Three patients with a spinal osteoid osteoma underwent pmRFA. The procedure was performed under computed tomography guidance using the 11 gauge Coblation SpineWand (ArthroCare). One lesion (at T11) was directly abutting the spinal canal. With an average follow-up of 20.7 (range 16-24) months, the mean Visual Analog Scale score for back pain decreased from 8.67 to 0.67 and no patient experienced tumor recurrence. pmRFA of spinal osteoid osteomas is feasible, even when the tumor is abutting the spinal canal. Larger studies with a longer follow-up are needed to further delineate the safety and efficacy of this technique.

The present report describes a technique for mitigating respiration-related microcatheter motion during endovascular aneurysm treatment by modulating ventilator settings. A rare phenomenon of microcatheter tip movement related to respiration is demonstrated. An adjustment of tidal volume and respiratory rate reduced the degree of inspiratory vessel elongation and stabilized the microcatheter position, allowing for safer, more precise coil deployment. This maneuver can easily be applied to other endovascular procedures for which aberrant microcatheter motion must be minimized.

Introduction: Aneurysm recurrence is a principle limitation of endovascular coiling procedures, with recurrence rates reported of >30%. The adjunct use of self-expandable stents has revolutionized the treatment of intracranial aneurysms, especially for complex morphologies, wide necks or unfavorable dome to neck ratios. However, further investigation into the durability and outcomes of stent assisted coiling procedures is required., Methods: The records of a prospective single center aneurysm database were retrospectively reviewed, and 90 consecutive patients with paraophthalmic aneurysms who underwent coil embolization were identified, 30 of which included stent placement. Patient demographics, aneurysm characteristics, coil packing density, angiographic results (initial and follow-up) and complications were analyzed., Results: Complete aneurysm occlusion was obtained on initial angiography in 13/30 (43.3%) stented and 19/60 (31.7%) non-stented patients. At ≤24 months (mean follow-up 12.8±6.2 months for stented and 12.8±6.6 months for non-stented group), aneurysm recurrence occurred in 3/26 (11.5%) stented and 14/39 (35.9%) non-stented patients (p<0.05). At the longest follow-up (mean 14.5±12.5 months for stented and 37.6±35.3 months for non-stented), aneurysm recurrence occurred in 4/26 (15.4%) stented and 17/41 (41.5%) non-stented patients (p<0.03). There was no statistically significant correlation between recurrence and aneurysm size or coiling packing., Conclusions: Following endovascular coil embolization of paraophthalmic region aneurysms, recurrence rates at 2 years were significantly lower in patients who had stent assisted coiling (11.5%) compared with patients who had coiling procedures without the use of a stent (35.9%). Aneurysm size and coiling packing density did not significantly affect recurrence in our study population.

Background: Bioactive polyglycolic/polylactic acid (PGLA)-coated Matrix detachable coils were reported to incite intra-aneurysmal inflammation and fibrosis. Multiple large case series with Matrix-1 coils have shown no advantage with respect to aneurysm recurrence. Second-generation Matrix-2 coils were designed with improved platinum support and reduced copolymer friction. We assessed the safety and efficacy of Matrix-2 coil embolization., Methods: 84 aneurysms were embolized primarily with Matrix-2 coils. Anatomic results were evaluated using a modified Raymond scale with progressive occlusion or recanalization/recurrence strictly defined as any interval change in intra-aneurysmal opacification., Results: Mid-term (8.9 ± 3.4 months) and long-term (23.0 ± 7.4 months) follow-up was available for 65 aneurysms. At mid-term, 55 (85%) aneurysms remained stable (or progressed to occlusion) versus 10 (15%) recurrent aneurysms, 7 (11%) requiring retreatment. At long term, 49 (75%) aneurysms remained stable versus 16 (25%) recurrent aneurysms, 12 (18%) requiring retreatment. Statistically significant factors affecting recanalization included ruptured aneurysms 9/20 (45%), large aneurysms 5/8 (71%), post-procedure residual aneurysms 6/12 (50%) and differential coil packing density of recurrent (21%) versus stable (28%) aneurysms. Patient morbidity (5%) was limited to thromboembolic complications (n=4) or aneurysm rerupture (n=1). Patient mortality (5%) was secondary to subarachnoid hemorrhage complications (n=4) with no procedure-related deaths (0%)., Conclusion: Coil embolization with Matrix-2 coils is safe and effective, preventing recanalization in small aneurysms at mid-term. Although these aneurysm recurrence rates initially appeared lower than previous reports with Matrix-1 or platinum coils, significant late recanalization was observed on long-term follow-up. We postulate that any derived benefit from Matrix-2 coils is directly dependent on post-procedure outcomes and coil packing density.

Background and Purpose: Reversible cerebral vasoconstriction syndromes (RCVS) represent a heterogeneous group of cerebrovascular disease characterized by acute presentations and transient segmental narrowing of the distal intracranial arteries. A series of patients with RCVS were studied to better understand the clinical and imaging characteristics of this rare pathology., Methods: A retrospective study was performed on patients that met inclusion criteria for a diagnosis of RCVS. Pertinent clinical and laboratory data, initial and follow-up imaging, treatment and outcomes were studied., Results: 11 patients (10 women, mean age 42 years) diagnosed with RCVS presented with acute onset of severe headache, neurological symptoms and subarachnoid hemorrhage (SAH). Cross sectional imaging (CT/MRI) identified presentations of cortical SAH (n=9) and/or acute infarcts (n=3). Initial cerebral angiography (digital subtraction angiography n=10 or MR angiography n=1) confirmed diffuse vasoconstriction involving the intracranial vasculature. Rheumatological panel (n=9) and CSF analysis (n=8) were not supportive of vasculitis in any patient. In nearly all cases, reversal of vasoconstriction was noted on follow-up cerebral angiography with early resolution in less than 3 months., Conclusions: RCVS classically presents with 'thunderclap' headaches and neurological symptoms but cortical SAH is not an uncommon presentation with a unique and focal distribution overlying the cerebral sulci. Although the initial clinical and angiographic appearance of RCVS may be confused for vasospasm related to aneurysmal SAH or primary angiitis of the CNS, its clinical, laboratory and imaging features assist in diagnosis.