The Impact of Dual Antiplatelet Therapy Duration on Unruptured Aneurysm Occlusion After Flow Diversion: A Multicenter Study.

OBJECTIVE: Endoluminal flow diversion reduces blood flow into intracranial aneurysms, promoting thrombosis. Postprocedural dual antiplatelet therapy (DAPT) is necessary for the prevention of thromboembolic complications. The purpose of this study is to therefore assess the impact that the type and duration of DAPT has on aneurysm occlusion rates and iatrogenic complications after flow diversion. METHODS: A retrospective review of a multicenter aneurysm database was performed from 2012 to 2020 to identify unruptured intracranial aneurysms treated with single device flow diversion and ≥12-month follow-up. Clinical and radiologic data were analyzed with aneurysm occlusion as a function of DAPT duration serving as a primary outcome measure. RESULTS: Two hundred five patients underwent flow diversion with a single pipeline embolization device with 12.7% of treated aneurysms remaining nonoccluded during the study period. There were no significant differences in aneurysm morphology or type of DAPT used between occluded and nonoccluded groups. Nonoccluded aneurysms received a longer mean duration of DAPT (9.4 vs 7.1 months, P = 0.016) with a significant effect of DAPT duration on the observed aneurysm occlusion rate (F(2, 202) = 4.2, P = 0.016). There was no significant difference in the rate of complications, including delayed ischemic strokes, observed between patients receiving short (≤6 months) and prolonged duration (>6 months) DAPT (7.9% vs 9.3%, P = 0.76). CONCLUSIONS: After flow diversion, an abbreviated duration of DAPT lasting 6 months may be most appropriate before transitioning to low-dose aspirin monotherapy to promote timely aneurysm occlusion while minimizing thromboembolic complications.

Treatment Approaches and Outcomes for Acute Anterior Circulation Stroke Patients with Tandem Lesions.

OBJECTIVES: Endovascular thrombectomy (EVT) has revolutionized stroke care for large vessel occlusions (LVOs). However, over half treated remain functionally disabled or die. Patients with tandem lesions, or severe stenosis/occlusion of the cervical internal carotid artery (ICA) with intracranial LVO, may have technical EVT challenges and worse outcomes. We sought to compare treatments and outcomes for patients with anterior circulation tandem lesions versus isolated LVOs. MATERIALS AND METHODS: Consecutive tandem lesion and isolated intracranial LVO patients were identified at a single center. Demographics, medical history, presentations, treatments, and outcomes were collected and analyzed. RESULTS: From 381 EVT patients, 62 had tandem lesions related to atherosclerosis (74%) or dissection (26%). Compared to isolated intracranial LVOs, they were younger (63 vs 70, p = 0.003), had less atrial fibrillation (13% vs 40%, p < 0.0001), less adequate reperfusion (TICI 2b-3, 58% vs 82%, p < 0.0001), more intracranial hemorrhage (ICH, 13% vs 5%, p = 0.037), but similar 90-day functional independence (mRS 0-2, 34% vs 43%, p = 0.181). The cervical ICA was treated before intracranial EVT (57%), after (13%), not acutely (22%), or was inaccessible (8%). Acute cervical ICA treatments were stenting (57%) or angioplasty alone (13%). Neither acute stenting nor order of treatment was associated with outcomes (TICI 2b-3, ICH, or 90-day mRS 0-2). Among acutely stented, neither alteplase nor antiplatelets were associated with outcomes or stent patency. CONCLUSIONS: Tandem lesions were associated with less reperfusion, more ICH, but similar 90-day functional independence. No treatment approach was associated with outcomes. These data illustrate the technical challenges of tandem lesion treatment and underscore the importance of developing new approaches.

Mechanical Thrombectomy in Stroke from Infective Endocarditis: Case Report and Review.

OBJECTIVE: To characterize outcomes after mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) from infective endocarditis. METHODS: Case report and review of published cases. RESULTS: We report the case of a 59-year-old woman with fungal endocarditis who developed AIS from a proximal middle cerebral artery (MCA) embolus. She underwent MT, with good outcome. An additional 25 similar cases were identified from 14 publications. Among the 26 cases analyzed (mean [SD] age, 55 [18.7] years, 42% women), the MCA was the most common site of arterial occlusion. Four patients received intravenous tissue plasminogen activator treatment before MT. The median admission NIH Stroke Scale score (NIHSSS) was 15.5 [interquartile range 9.75-19.25] and the median post-procedure NIHSSS was 2 [interquartile range .75-6]. No patient developed symptomatic intracerebral hemorrhage. CONCLUSIONS: MT appears to be a safe and effective therapeutic option in infective endocarditis-related AIS with proximal-artery occlusion.

Does including neck CTA in work-up of suspected intracranial hemorrhage add value?

PURPOSE: Neck CT angiography (CTA) is frequently performed in conjunction with head CTA in patients presenting with clinical signs and symptoms concerning for acute intracranial hemorrhage, despite relatively low appropriateness (ACR Appropriateness Criteria 2-6). This decision is sometimes justified by suggesting that CTA neck findings are useful in planning subsequent catheter angiography. METHODS: We investigated the value of neck CTA in patients with suspected acute intracranial hemorrhage by reviewing 220 head and neck CTAs performed in our emergency room over a 24-month period for the indication of hemorrhage or headache. Images were reviewed by two neurointerventionalists to address the value of the neck CTA for planning catheter angiography. RESULTS: Findings helpful for performing catheter angiography were observed on neck CTA in 22% (Cohen kappa 0.65), and included anatomical arch variants such as a bovine arch, direct vertebral artery arch origin, and aberrant subclavian artery. However, findings that might substantially prolong angiography for more than 10 min if unknown occurred in 5% (Cohen kappa 0.69). Incidental findings prompting additional imaging or significant clinical action occurred in 20%. Subarachnoid hemorrhage on noncontrast head CT was strongly associated with a need for subsequent angiography. CONCLUSIONS: Although CTA neck can provide helpful information for planning catheter angiography, it rarely uncovers findings that would significantly prolong the procedure if unknown. Neck CTA is therefore only recommended in patients with a confirmed intracranial hemorrhage in a pattern consistent with aneurysm or arteriovenous shunt.

Left Thalamus Arteriovenous Malformation Secondary to Radiation Therapy of Original Vermian Arteriovenous Malformation: Case Report.

A 70-year-old gentleman with history of hypothyroidism, hyperlipidemia, hypertension, and right superior cerebellar aneurysm presented to the neurosurgery service in 2008 with vertigo. Diagnostic cerebral angiography performed that year demonstrated a vermian arteriovenous malformations (AVM). The patient underwent stereotactic proton beam radiosurgery, which resulted in a decrease in flow and size of the lesion, and the patient was lost to follow-up. Now at the age of 80, the patient presented with acute gait instability. Cerebral angiogram demonstrated his stable vermian AVM and a new 1.1 cm AVM nidus in the region of the left posterior thalamus. Although AVMs are often described as congenital lesions, there is a growing body of literature suggesting that AVMs can grow, spontaneously regress, and even arise de novo in response to some insult. Understanding what leads to the growth, remodeling, regression, and hemorrhage of AVMs is crucial in order to better direct therapeutic endeavors. We would argue that this patient's AVM is secondary to endothelial cell damage from radiation therapy. Radiation can cause endothelial cell injury and upregulation of factors, such as vascular endothelial growth factor and transforming growth factor beta expression, which are implicated in AVM development pathways. We believe that this patient's new AVM is secondary to entrance radiation dosing affecting the thalamus during radiation therapy for the original vermian AVM.

CT and MRI of Rare Extraintestinal Manifestations of Inflammatory Bowel Disease in Children and Adolescents.

Inflammatory bowel disease (IBD) is associated with a spectrum of extraintestinal manifestations (EIMs) affecting many organ systems. EIMs can occur in more than 40% of patients with IBD and are associated with significant morbidity. They occur at any time point in the course of disease, often during an active phase of bowel inflammation, but sometimes preceding bowel disease. Prompt recognition of EIMs enables timely and more effective therapy. Physicians who image patients with IBD should be aware of the myriad extraintestinal conditions that may be detected on imaging studies, both within and outside of the abdomen, as they may predate the diagnosis of IBD. Cross-sectional imaging of unusual conditions associated with IBD will be presented, including pathology in the hepatobiliary, pancreatic, genitourinary, musculoskeletal, mucocutaneous, vascular, neurologic, and pulmonary systems.

The Impact of Preprocedural Platelet Function Testing on Periprocedural Complication Rates Associated With Pipeline Flow Diversion: An International Multicenter Study.

BACKGROUND AND OBJECTIVES: Dual antiplatelet therapy (DAPT) is necessary to minimize the risk of periprocedural thromboembolic complications associated with aneurysm embolization using pipeline embolization device (PED). We aimed to assess the impact of platelet function testing (PFT) on reducing periprocedural thromboembolic complications associated with PED flow diversion in patients receiving aspirin and clopidogrel. METHODS: Patients with unruptured intracranial aneurysms requiring PED flow diversion were identified from 13 centers for retrospective evaluation. Clinical variables including the results of PFT before treatment, periprocedural DAPT regimen, and intracranial complications occurring within 72 h of embolization were identified. Complication rates were compared between PFT and non-PFT groups. Differences between groups were tested for statistical significance using the Wilcoxon rank sum, Fisher exact, or χ 2 tests. A P -value <.05 was statistically significant. RESULTS: 580 patients underwent PED embolization with 262 patients dichotomized to the PFT group and 318 patients to the non-PFT group. 13.7% of PFT group patients were clopidogrel nonresponders requiring changes in their pre-embolization DAPT regimen. Five percentage of PFT group [2.8%, 8.5%] patients experienced thromboembolic complications vs 1.6% of patients in the non-PFT group [0.6%, 3.8%] ( P = .019). Two (15.4%) PFT group patients with thromboembolic complications experienced permanent neurological disability vs 4 (80%) non-PFT group patients. 3.7% of PFT group patients [1.5%, 8.2%] and 3.5% [1.8%, 6.3%] of non-PFT group patients experienced hemorrhagic intracranial complications ( P > .9). CONCLUSION: Preprocedural PFT before PED treatment of intracranial aneurysms in patients premedicated with an aspirin and clopidogrel DAPT regimen may not be necessary to significantly reduce the risk of procedure-related intracranial complications.

Anomalous PiB enhancement in the superior sagittal and transverse venous sinuses.

Pittsburgh compound-B (PiB), an amyloid-binding positron emission tomography (PET) tracer, is widely used for imaging amyloid-ß in those with and at risk for Alzheimer disease. Here, we report on an otherwise normal 68-year-old female with abnormally high and very focal PiB retention. Coregistered T1-weighted magnetic resonance imaging and dynamic 2-fluoro-2-deoxy-D-glucose (FDG) images confirmed that the focal PiB enhancement was in the superior sagittal and transverse sinuses, outside of the adjacent cortex. Flow through the venous vasculature was normal as assessed by dynamic FDG PET imaging. These features supported the conclusion that PiB retention was not simply due to a hemodynamic abnormality, but may have represented PiB binding to fibrillar deposits of a ß-sheet protein (ie, amyloid), whose nature is currently unclear.

Angiographic Pulse Wave Coherence in the Human Brain.

A stroke volume of arterial blood that arrives to the brain housed in the rigid cranium must be matched over the cardiac cycle by an equivalent volume of ejected venous blood. We hypothesize that the brain maintains this equilibrium by organizing coherent arterial and venous pulse waves. To test this hypothesis, we applied wavelet computational methods to diagnostic cerebral angiograms in four human patients, permitting the capture and analysis of cardiac frequency phenomena from fluoroscopic images acquired at faster than cardiac rate. We found that the cardiac frequency reciprocal phase of a small region of interest (ROI) in a named artery predicts venous anatomy pixel-wise and that the predicted pixels reconstitute venous bolus passage timing. Likewise, a small ROI in a named vein predicts arterial anatomy and arterial bolus passage timing. The predicted arterial and venous pixel groups maintain phase complementarity across the bolus travel. We thus establish a novel computational method to analyze vascular pulse waves from minimally invasive cerebral angiograms and provide the first direct evidence of arteriovenous coupling in the intact human brain. This phenomenon of arteriovenous coupling may be a physiologic mechanism for how the brain precisely maintains mechanical equilibrium against volume displacement and kinetic energy transfer resulting from cyclical deformations with each heartbeat. The study also paves the way to study deranged arteriovenous coupling as an underappreciated pathophysiologic disturbance in a myriad of neurological pathologies linked by mechanical disequilibrium.

Determinants of intracranial aneurysm retreatment following embolization with a single flow-diverting stent.

PURPOSE: Flow diverting stents have revolutionized the treatment of intracranial aneurysms through endoluminal reconstruction of the parent vessel. Despite this, certain aneurysms require retreatment. The purpose of this study was to identify clinical and radiologic determinants of aneurysm retreatment following flow diversion. METHODS: A multicenter flow diversion database was evaluated to identify patients presenting with an unruptured, previously untreated aneurysm with a minimum of 12 months' clinical and angiographic follow-up. Univariate and multivariate logistic regression modeling was performed to identify determinants of retreatment. RESULTS: We identified 189 aneurysms treated in 189 patients with a single flow-diverting stent. Mean age was 54 years, and 89% were female. Complete occlusion was achieved in 70.3% and 83.6% of patients at six and 12 months, respectively. Aneurysm retreatment with additional flow-diverting stents occurred in 5.8% of cases. Univariate analysis revealed that dome diameter ≥10 mm (p = 0.012), pre-clinoid internal carotid artery location (p = 0.012), distal > proximal parent vessel diameter (p = 0.042), and later dual antiplatelet therapy (DAPT) discontinuation (p < 0.001) were predictive of retreatment. Multivariate analysis identified discontinuation of DAPT >12 months (p = 0.003) as a strong determinant of retreatment with dome diameter ≥10 mm trending toward statistical significance (p = 0.064). Large aneurysm neck diameter, presence of aneurysm branch vessels, patient age, smoking history, and hypertension were not determinant of retreatment on multivariate analysis. CONCLUSIONS: Prolonged DAPT is the most important determinant of aneurysm retreatment following single-device flow diversion. Abbreviating DAPT duration to only six months should be a consideration in this population, especially for patients with a large aneurysm dome diameter.

Current Clinical Applications of Intracranial Vessel Wall MR Imaging.

Intracranial vessel wall MR imaging (VWI) is increasingly being used as a valuable adjunct to conventional angiographic imaging techniques. This article will provide an updated review on intracranial VWI protocols and image interpretation. We review VWI technical considerations, describe common VWI imaging features of different intracranial vasculopathies and show illustrative cases. We review the role of VWI for differentiating among steno-occlusive vasculopathies, such as intracranial atherosclerotic plaque, dissections and Moyamoya disease. We also highlight how VWI may be used for the diagnostic work-up and surveillance of patients with vasculitis of the central nervous system and cerebral aneurysms.

Long-term follow-up results of the SMART coil in the endovascular treatment of intracranial aneurysms.

BACKGROUND: The Penumbra SMART coil is a novel device that becomes progressively softer from its distal to proximal end to maximize coil packing and prevent microcatheter prolapse or coil migration. Here, we report a large series of patients detailing the long-term experience of a single institution using the SMART coil among patients with intracranial aneurysms (IAs). METHODS: Prospective data of 105 consecutive patients with 106 IAs treated using SMART coils was collected between March 2015 and July 2018. Clinical and angiographic data were analyzed. RESULTS: Forty-nine patients (46.7%) presented with subarachnoid hemorrhage and 16 (14.2%) had recurrent aneurysms. Two patients had minor intraprocedural ruptures and remained neurologically stable. One patient had a thromboembolic complication with progressive neurologic decline. There was only one case microcatheter prolapse related to placement of a stent before coiling. An initial post-treatment modified Raymond-Roy Occlusion Classification (mRROC) I or II closure was achieved in 56 (52.8%) aneurysms. The average time to last follow-up was 8.4 months at which 70 (81.4%) aneurysms had mRROC I or II occlusion and a major recurrence was seen in 5 (5.8%) patients. Thirteen (12.3%) aneurysms required re-treatment of which one aneurysm was clipped. CONCLUSIONS: The Penumbra SMART coil is safe and effective for the endovascular treatment of appropriately selected IAs. Additional studies at multiple centers comparing safety and efficacy profile over long-term periods to other mainstream coils are necessary.

Cause determination of missed lung nodules and impact of reader training and education: Simulation study with nodule insertion software.

BACKGROUND: There are "blind spots" on chest computed tomography (CT) where pulmonary nodules can easily be overlooked. The number of missed pulmonary nodules can be minimized by instituting a training program with particular focus on the depiction of nodules at blind spots. PURPOSE: The purpose of this study was to assess the variation in lung nodule detection in chest CT based on location, attenuation characteristics, and reader experience. MATERIALS AND METHODS: We selected 18 noncalcified lung nodules (6-8 mm) suspicious of primary and metastatic lung cancer with solid (n = 7), pure ground-glass (6), and part-solid ground-glass (5) attenuation from 12 chest CT scans. These nodules were randomly inserted in chest CT of 34 patients in lung hila, 1st costochondral junction, branching vessels, paramediastinal lungs, lung apices, juxta-diaphragm, and middle and outer thirds of the lungs. Two residents and two chest imaging clinical fellows evaluated the CT images twice, over a 4-month interval. Before the second reading session, the readers were trained and made aware of the potential blind spots. Chi-square test was used to assess statistical significance. RESULTS: Pretraining session: Fellows detected significantly more part-solid ground-glass nodules compared to residents (P = 0.008). A substantial number of nodules adjacent to branching vessels and posterior mediastinum were missed. Posttraining session: There was a significant increase in detectability independent of attenuation and location of nodules for all readers (P < 0.0008). CONCLUSION: Dedicated chest CT training improves detection of lung nodules, especially the part-solid ground-glass nodules. Detection of nodules adjacent to branching vessels and the posterior mediastinal lungs is difficult even for fellowship-trained radiologists.

Initial experience with React 68 aspiration catheter.

INTRODUCTION: We describe our initial experience with the React 68 catheter (Medtronic, Dublin, Ireland), an FDA-approved catheter designed for aspiration in cases of emergent large vessel occlusion, as compared with the ACE 68 catheter (Penumbra, Alameda, CA). METHODS: This observational study followed consecutive patients treated with the React catheter over a seven-month period at a comprehensive stroke center. Use of the device was per discretion of the operator. Patient demographics, thrombectomy technique, reperfusion scoring, and disposition were assessed. Performance was compared with patients treated with the ACE 68 catheter over a comparable period. RESULTS: We treated 47 patients using the React 68 catheter using either aspiration alone or a combination of aspiration and stent retriever technique. The catheter was used in a variety of circumstances including proximal and distal occlusions involving the anterior and posterior circulation. Modified TICI 2b-3 was achieved in 45 of the 47 patients. The React 68 was comparable to the ACE 68 by all performance measures. CONCLUSION: The React 68 catheter is a large-bore reperfusion catheter with trackability suitable for use in direct aspiration for recanalization of emergent large vessel occlusion.

Design, synthesis, and testing of difluoroboron-derivatized curcumins as near-infrared probes for in vivo detection of amyloid-beta deposits.

Amyloid-beta (Abeta) deposits have been identified as key players in the progression of Alzheimer's disease (AD). Recent evidence indicates that the deposits probably precede and induce the neuronal atrophy. Therefore, methods that enable monitoring the pathology before clinical symptoms are observed would be beneficial for early AD detection. Here, we report the design, synthesis, and testing of a curcumin-derivatized near-infrared (NIR) probe, CRANAD-2. Upon interacting with Abeta aggregates, CRANAD-2 undergoes a range of changes, which include a 70-fold fluorescence intensity increase, a 90 nm blue shift (from 805 to 715 nm), and a large increase in quantum yield. Moreover, this probe also shows a high affinity for Abeta aggregates (K(d) = 38.0 nM), a reasonable log P value (log P = 3), considerable stability in serum, and a weak interaction with albumin. After intravenous injection of this probe, 19-month-old Tg2576 mice exhibited significantly higher relative signal than that of the control mice over the same period of time. In summary, CRANAD-2 meets all the requirements for a NIR contrast agent for the detection of Abeta plaques both in vitro and in vivo. Our data point toward the feasibility of monitoring the progress of the disease by NIR imaging with CRANAD-2. In addition, we believe that our probe could be potentially used as a tool for drug screening.

Vessel Wall MRI Added to MR Angiography in the Evaluation of Suspected Vasculopathies.

BACKGROUND AND PURPOSE: We hypothesized that vessel wall MR imaging (VWI) with 3D-time-of-flight magnetic resonance imaging (3D-TOF-MRA) together increases the ability to detect abnormal intracranial vessel segments compared to 3D-TOF-MRA alone. METHODS: Ninety-three consecutive subjects with a clinical history of suspected vasculopathy imaged with both VWI and 3D-TOF-MRAs were retrospectively reviewed. The 3D-TOF-MRAs were reviewed by two independent neuroradiologists classifying arterial segments as normal or abnormal based on caliber changes. Following a 2-week wash-out period, the 3D-TOF-MRAs with VWI together were re-evaluated for caliber changes and/or vessel wall enhancement. A third neuroradiologist served as consensus. Significance was assessed by McNemar's test. RESULTS: Forty-two subjects with VWI and 3D-TOF-MRAs met the inclusion criteria. By 3D-TOF-MRA alone, 12.3% (95% confidence interval [CI], 10.7-15.1) of the arterial segments were identified as abnormal compared to 20.8% (95% CI, 18.2-23.4) by VWI and 3D-TOF-MRA together (P < .0001). CONCLUSIONS: 3D-TOF-MRA and VWI together identifies a higher number of abnormal vessel segments than 3D-TOF-MRA alone and may provide a more accurate assessment of disease burden.

High resolution vessel wall MR imaging in prestenotic intracranial atherosclerotic disease.

Vessel wall MR imaging (VWI) may be able to highlight vulnerable intracranial atherosclerosis with vessel wall enhancement thereby serving as a biomarker for symptomatic prestenotic intracranial atherosclerotic disease. We present a case of intracranial hemorrhage presumably due to intracranial atherosclerotic disease (ICAD) identified by VWI and silent on lumen-based imaging modalities. A 66-year-old female presented with sudden onset headache and dysarthria. A head CT showed intracranial hemorrhage centered in the right basal ganglia. Further imaging by CT angiography, MR angiography and a conventional catheter angiogram were negative. MRI of the brain, including VWI, showed abnormal enhancement in the right middle cerebral artery vessel wall, suggesting intracranial atherosclerotic changes in a prestenotic vessel. As a potential noninvasive screening test, VWI could impact patients with ICAD and become part of a stroke risk stratification algorithm.

Spatial Distribution of Intracranial Vessel Wall Enhancement in Hypertension and Primary Angiitis of the CNS.

We hypothesized a difference in the spatial distribution of intracranial vessel wall enhancement between CNS vasculitis and risk factors for intracranial atherosclerotic disease (ICAD). Fifty-five vessel wall MR imaging (VWI) exams were included in this retrospective observational study. Intracranial arteries were evaluated for vessel wall enhancement by branching pattern (e.g., primary, secondary, and tertiary segments). Demographic and laboratory data as well as ICAD risk factors, including a diagnosis of hypertension, were collected. A diagnosis of primary angiitis of the CNS (PACNS) was confirmed by biopsy or clinical assessment by a stroke neurologist. Univariate and multivariate Poisson regression models were fit for the outcomes. In multivariate analyses, hypertension showed significant associations with primary (ß = 1.31, 95% CI 0.78-1.88, p < 0.0001) and secondary (ß = 1.15, 95% CI 0.29-2.18, p = 0.05) segments, contrasting with PACNS which showed a distal spatial distribution with significant associations with secondary (ß = 0.77, 95% CI 0.14-1.39, p = 0.05) and tertiary (ß = 1.34, 95% CI 0.68-2.01, p < 0.0001) segments. Our results suggest the spatial distribution of vessel wall enhancement is an important consideration when interpreting VWI exams, particularly in patients with a comorbid diagnosis of hypertension. Given the global prevalence of hypertension, these results are impactful and may improve image interpretation of VWI in stroke patients.

Comparison of predictive grading systems for procedural risk in endovascular treatment of brain arteriovenous malformations: analysis of 104 consecutive patients.

OBJECTIVE: Several grading systems for procedural risk in the endovascular treatment of brain arteriovenous malformations (AVMs) have been proposed, including the Buffalo, Puerto Rico, and AVM embocure scoring systems. The authors sought to validate these systems in an independent patient cohort and compare each system to the established Spetzler-Martin (SM) scale. METHODS: One hundred four consecutive patients underwent adjunctive endovascular embolization of brain AVMs between 2002 and 2016 with the goal of reducing the surgical or hemorrhagic risk before definitive radiosurgical treatment. Baseline clinical and AVM characteristics, complications, and degree of AVM nidus reduction were obtained retrospectively. Univariate and multivariate comparisons and receiver operating characteristic (ROC) curve analyses were performed. RESULTS: Ten major (9.6%) and 16 minor (15.4%) complications were encountered in 24 patients (23.1%). An arterial pedicle size < 1 mm (p = 0.001) and a greater number of pedicles (p = 0.039) were predictors of complication occurrence. Only the Buffalo score predicted the complication rate on univariate (p = 0.039) and multivariate (p = 0.001) analyses. ROC curve analysis revealed a greater area under the curve (AUC) of the Buffalo score (0.703) compared to the Puerto Rico score (p = 0.028), AVM embocure score (AVMES; p = 0.010), and SM grade (SMG; p = 0.030). The Buffalo score, Puerto Rico score, and AVMES but not the SMG predicted > 85% nidus reduction. The AUCs for the different scoring systems were not significantly different. CONCLUSIONS: The major complication rate of 9.6% is within the range of rates reported in the literature and emphasizes that brain AVM embolization is not a low-risk procedure. The Buffalo score but not the Puerto Rico score, AVMES, or SMG predicted the endovascular procedural risk. All three endovascular scores but not the SMG predicted a > 85% nidus reduction rate in this cohort embolized as part of a multimodal AVM treatment.

The Role of Collateral Circulation in Branch Vessel Occlusion After Flow Diversion.

BACKGROUND: Flow diversion for treatment of intracranial aneurysms frequently necessitates covering adjacent branch vessels. Although branch vessel occlusion is common, associated clinical deficits are rare. It has been hypothesized that clinically silent branch vessel occlusion is due to underlying collateral circulation. To study the role of collateral circulation in covered branch vessel occlusion, we assessed collateral vessels and altered branch vessel flow on transfemoral catheter angiography in patients undergoing flow diversion of intracranial aneurysms. METHODS: Angiograms obtained before treatment, immediately after treatment, and during follow-up were evaluated for branch vessel flow patterns and associated collateral circulation in a consecutive retrospective cohort of 84 patients from 2011 to 2017 with branch vessel coverage related to aneurysm flow diversion using the Pipeline embolization device. RESULTS: We identified 142 branch vessels covered by the Pipeline device construct for treatment of 89 aneurysms, predominately in the anterior circulation (>90%). Collateral circulation was observed in approximately one third of these vessels and was associated with diminished (P < 0.001) or absent (P < 0.001) flow on follow-up angiography. Only 2 of 80 terminal branch vessels (no collaterals) were occluded, and these occurred in a patient with Pipeline device construct thrombosis. Altered branch vessel flow was not associated with vascular risk factors, treatment technique, or outcome measures, including new or worsening neurologic deficit. CONCLUSIONS: Altered flow in branch vessels covered during flow diversion reflects underlying collateral circulation and is not associated with downstream ischemic deficits.