Pipeline Embolization device for the treatment of unruptured intracranial saccular aneurysms: a systematic review and meta-analysis of long-term outcomes.

INTRODUCTION: The pipeline embolization device (PED) is commonly used for intracranial aneurysm treatment. While its effectiveness for certain types of aneurysms is well-established, its efficacy for saccular aneurysms remains controversial. We aimed to assess the long-term outcomes of PED treatment for unruptured intracranial saccular aneurysms. METHODS: Systematic review and meta-analysis were conducted following PRISMA guidelines. Studies with at least one year of follow-up after PED treatment for saccular aneurysms were included. The primary endpoint was angiographic aneurysm occlusion at long-term follow-up (≥ 12 months), and the secondary outcome was long-term complications. We conducted a meta-regression analysis to explore potential sources of heterogeneity across studies. RESULTS: Eleven studies of 797 patients with 963 aneurysms were included. Long-term angiographic occlusion rate was 85% (95% CI, 77-91%; p < 0.01), symptomatic ischemic stroke rate was 1% (95% CI, 0-3%; p < 0.01), rupture rate was 1% (95% CI, 0-2%; p = 0.02), and intracranial hemorrhage (ICH) rate was 0.2% (95% CI, 0-1%; p = 0.11). Meta-regression analysis revealed a non-significant decreasing trend per year for aneurysmal occlusion, ischemic stroke rate, delayed aneurysmal rupture, and ICH. CONCLUSION: PED demonstrates high long-term occlusion and low complication rates, suggesting it is a safe and effective treatment option for saccular aneurysms. Additionally, newer devices exhibit reduced thrombogenic profiles and safety with decreasing trends in ICH, ischemic stroke, and delayed aneurysmal rupture.

The ABCs of Subarachnoid Hemorrhage Blood Volume Measurement: A Simplified Quantitative Method Predicts Outcomes and Delayed Cerebral Ischemia.

BACKGROUND: We developed a simplified ABC/2-derived method to estimate total subarachnoid hemorrhage volume (SAHV) on noncontrast computed tomography in patients with aneurysmal SAH and compared the clinical and radiographic outcomes. METHODS AND RESULTS: In this retrospective observational cohort study, we analyzed 277 patients with SAH admitted to our Comprehensive Stroke Center between 2012 and 2022. We derived a mathematical model (model 1) by measuring SAH basal cisternal blood volume using an ABC/2-derived ellipsoid formula (A=width/thickness, B=length, C=vertical extension) on head noncontrast computed tomography in 5 major SAH cisternal compartments. We compared model 1 against a manual segmentation method (model 2) on noncontrast computed tomography. Data were analyzed using logistic regression analysis, t test, receiver operator characteristic curves, and area under the curve analysis. There was no significant difference in cisternal SAHV analysis between the 2 models (P=0.14). Mean SAHV by the simplified method was 7.0 mL (95% CI, 5.89-8.09) for good outcome and 16.6 mL (95% CI, 13.49-19.77) for poor outcome. Patients with delayed cerebral ischemia had higher SAHV, with a cutoff value of 10 mL. CONCLUSIONS: Our simplified ABC/2-derived method to estimate SAHV is comparable to manual segmentation and can be performed in low-resource settings. Higher total SAHV was associated with worse outcomes and higher risk of delayed cerebral ischemia. A potential dose-response relationship was observed, with SAHV >10 mL predicting worse outcomes and higher risk of DCI.

Radiographic Anatomy of the Common Carotid Artery for Direct Carotid Puncture.

BACKGROUND: Direct common carotid puncture (DCP) is conventionally used as a bailout technique in stroke patients. However, little is known about the relevant anatomy. Our objective was to examine the relationship of the common carotid artery (CCA) to surrounding structures based on different DCP trajectories passing through the artery's center. METHODS: Fifty randomly selected head/neck CTAs were analyzed. The trajectory of DCP and relationship to the internal jugular vein (IJV) and thyroid were analyzed at 1 cm intervals above the clavicle on 7 axial sections. Using the trans-carotid sagittal plane as the 0° trajectory, we plotted 3 additional trajectories at 30° intervals and the relationship with the IJV and thyroid proximity was graded as following: 0=absent, 1=adjacent, and 2=crossing. The CCA tortuosity index was also analyzed for each vessel. RESULTS: Analysis of 2800 trajectories across 100 CCAs showed that the IJV and thyroid were least encountered on the axial sections 2 cm above the clavicle, at 0° on the right (9 thyroids and 6 IJV), and at 90° on the left (0 Thyroids and 14 IJVs). The tortuosity index of the CCA was significantly lower above the clavicle than its entire length (P < 0.001). CONCLUSIONS: DCP performed 2 cm above the clavicle at 0° on the right, and 90° on the left appears to minimize encounters with the IJV and thyroid gland, reducing potential complications. However, despite these findings, ultrasound guidance remains vital for DCP safety. Further focus on endovascular device safety in DCP is needed.

Impact of duration of dual anti-platelet therapy on risk of complications after stent-assisted coiling of unruptured aneurysms.

BACKGROUND: The optimal duration for dual antiplatelet therapy (DAPT) after stent-assisted coiling (SAC) of intracranial aneurysms is unclear. Longer-term therapy may reduce thrombotic complications but increase the risk of bleeding complications. METHODS: A retrospective review of prospectively maintained data at 12 institutions was conducted on patients with unruptured intracranial aneurysms who underwent SAC between January 1, 2016 and December 31, 2020, and were followed ≥6 months postprocedure. The type and duration of DAPT, stent(s) used, outcome, length of follow-up, complication rates, and incidence of significant in-stent stenosis (ISS) were collected. RESULTS: Of 556 patients reviewed, 450 met all inclusion criteria. Nine patients treated with DAPT <29 days after SAC and 11 treated for 43-89 days were excluded from the final analysis as none completed their prescribed duration of treatment. Eighty patients received short-term DAPT. There were no significant differences in the rate of thrombotic complications during predefined periods of risk in the short, medium, or long-term treatment groups (1/80, 1.3%; 2/188, 1.1%; and 0/162, 0%, respectively). Similarly, no differences were found in the rate of hemorrhagic complications during period of risk in any group (0/80, 0%; 3/188, 1.6%; and 1/162, 0.6%, respectively). Longer duration DAPT did not reduce ISS risk in any group. CONCLUSIONS: Continuing DAPT >42 days after SAC did not reduce the risk of thrombotic complications or in-stent stenosis, although the risk of additional hemorrhagic complications remained low. It may be reasonable to discontinue DAPT after 42 days following non-flow diverting SAC of unruptured intracranial aneurysms.

Intracranial aneurysms in patients with acute ischemic stroke prevalence and influence on mechanical thrombectomy over 14 years in a tertiary-care center.

INTRODUCTION: The prevalence of intracranial aneurysms (IA) in patients with acute ischemic stroke (AIS) requiring mechanical thrombectomy (MT) is unclear. OBJECTIVE: To describe the prevalence of IA in patients with AIS and their influence on MT. MATERIALS & METHODS: This is a retrospective cohort study on all patients admitted with a diagnosis of AIS from January 2008 to March 2022 at a tertiary academic center. The records were reviewed for demographic, clinical, imaging, and outcomes data. Only patients who had CTA at admission were included in this analysis. RESULTS: Among 2265 patients admitted with AIS, this diagnosis was confirmed in 2113 patients (93.3 %). We included 1111 patients (52.6 %) who had head CTA and 321 (28.9 %) who underwent MT. The observed prevalence of aneurysms on CTA was 4.5 % (50/1111 patients), and 8 (16 %) had multiple aneurysms. MT was performed in 7 patients harboring IAs: 6 ipsilateral (5 proximal and 1 distal to the occlusion)and 1 contralateral aneurysm.. The patient with a contralateral aneurysm had a TICI 2B score In patients with ipsilateral aneurysms, TICI 2B or 3 was achieved in 3 cases (50 %), which is significantly lower than historical control of MT (91.6 %) without IA (p = 0.01). No aneurysms ruptured during MT. The aneurysm noted distal to the occlusion was mycotic. CONCLUSION: In this analysis, the observed prevalence of IA in patients with AIS was 4.5%. Ipsilateral aneurysms (proximal or distal to the occlusion site) deserve particular attention, given the potential risk of rupture during MT. Aneurysms located distal to the occlusion were mycotic and the rate of recanization in patients with ipsilateral aneurysms was low compared to historical controls. Further studies are needed to improve the outcomes in patients with IA requiring MT.

Management of failed flow diversion for intracranial aneurysm beyond the first 6 months of follow-up: an international Delphi consensus.

OBJECTIVE: The placement of flow-diverting devices has become a common method of treating unruptured intracranial aneurysms of the internal carotid artery. The progressive improvement of aneurysm occlusion after treatment-with low complication and rupture rates-has led to a dilemma regarding the management of aneurysms in which occlusion has not occurred within 6-24 months. The authors aimed to identify clinical consensus regarding management of intracranial aneurysms displaying persistent filling 6-24 months after flow diversion and to ascertain questions that may drive future investigation. METHODS: An international panel of 67 experts was invited to participate in a multistep Delphi consensus process on the treatment of intracranial aneurysms after failed flow diversion. RESULTS: Of the 67 experts invited, 23 (34%) participated. Qualitative analysis of an initial survey with open-ended questions resulted in 51 statements regarding management of aneurysms showing persistent filling after flow diversion. The statements were grouped into 8 categories, and in the second round, respondents rated the degree of their agreement with each statement on a 5-point Likert scale. Flow diverters with surface modifiers did not influence administration of dual-antiplatelet therapy according to 83%. Consensus was also reached regarding the definition of treatment failure at specific time points, including at 6 months if there is aneurysm growth or persistent rapid flow through the entirety of the aneurysm (96%), at 12 months if there is aneurysm growth or symptom onset (78%), and at 24 months if there is persistent filling regardless of size and filling characteristics (74%). Although experts agreed that the degree of intimal hyperplasia or in-device stenosis could not be ascertained by noninvasive imaging alone (83%), only 65% chose digital subtraction angiography as the preferred modality. At 6 and 12 months, retreatment is preferred if there is persistent filling with aneurysm growth (96%, 96%), device malposition (48%, 87%), or a history of subarachnoid hemorrhage (65%, 70%), respectively, and at 24 months if there is persistent filling without reduction in aneurysm size (74%). Experts favored treatment with an additional flow diverter (87%) over aneurysm clipping, applying the same principles for follow-up (83%) and treatment failure (91%) as for the first flow diverter. CONCLUSIONS: The authors present the consensus practices of experts in the management of intracranial aneurysms without occlusion 6-24 months after treatment with a flow-diverting device.

Long-Term Safety and Efficacy of Pipeline Embolization Device in Anterior and Posterior Circulation Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND: Flow diversion using the pipeline embolization device (PED) has been a paradigm shift for anterior circulation (AC) aneurysms. However, only a few studies report the long-term (≥1 year) angiographic and clinical outcomes for posterior circulation (PC) aneurysms. This study aims to compare the long-term safety and efficacy of treatment of AC and PC aneurysms with PED. METHODS: The databases included Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane, and Scopus. Studies with at least 10 patients and 1-year follow-up were included. Twenty-four studies met our inclusion criteria. A random effect meta-analysis was performed to estimate the ischemic and hemorrhagic complications. A meta-analysis of proportions was performed to estimate the pooled rates of long-term complete aneurysmal occlusion, symptomatic stroke, aneurysmal rupture, and intracranial hemorrhage. RESULTS: There were 1952 aneurysms, of which 1547 (79.25%) were in the AC and 405 (20.75%) in the PC. The 1-year occlusion rate was 78% in AC compared to 73% in PC aneurysms (P < 0.01). The symptomatic infarct rate was 5% in AC compared to 13% in PC (P < 0.01). While the rupture rate was 1% in AC compared to 4% in PC (P = 0.01), the rate of intracranial hemorrhage was 2% for both (P = 0.99). CONCLUSIONS: The long-term occlusion rate after PED was higher in AC aneurysms, and the cumulative incidence of stroke and aneurysm rupture was higher in PC aneurysms.

Impact of the pandemic and concomitant COVID-19 on the management and outcomes of middle cerebral artery strokes: a nationwide registry-based study.

OBJECTIVES: To investigate the impact of the COVID-19 pandemic as well as concomitant COVID-19 itself on stroke care, focusing on middle cerebral artery (MCA) territory infarctions. DESIGN: Registry-based study. SETTING: We used the National Inpatient Sample (NIS) database, which covers a wide range of hospitals within the USA. PARTICIPANTS: The NIS was queried for patients with MCA strokes between 2016 and 2020. In total, 35 231 patients were included. OUTCOME MEASURES: Outcome measures were postprocedural complications, length of stays (LOSs), in-hospital mortality and non-routine discharge. Propensity score matching using all available baseline variables was performed to reduce confounders when comparing patients with and without concomitant COVID-19. RESULTS: Mechanical thrombectomy (MT) was performed in 48.4%, intravenous thrombolysis (IVT) in 38.2%, and both MT and IVT (MT+IVT) in 13.4% of patients. A gradual increase in the use of MT and an opposite decrease in the use of IVT (p<0.001) was detected during the study period. Overall, 25.0% of all patients were admitted for MCA strokes during the pandemic period (2020), of these 209 (2.4%) were concomitantly diagnosed with COVID-19. Patients with MCA strokes and concomitant COVID-19 were significantly younger (64.9 vs 70.0; p<0.001), had significantly worse NIH Stroke Severity scores, and worse outcomes in terms of LOS (12.3 vs 8.2; p<0.001), in-hospital mortality (26.3% vs 9.8%; p<0.001) and non-routine discharge (84.2% vs 76.9%; p=0.013), as compared with those without COVID-19. After matching, only in-hospital mortality rates remained significantly higher in patients with COVID-19 (26.7% vs 8.5%; p<0.001). Additionally, patients with COVID-19 had higher rates of thromboembolic (12.3% vs 7.6%; p=0.035) and respiratory (11.3% vs 6.6%; p=0.029) complications. CONCLUSIONS: Among patients with MCA stroke, those with concomitant COVID-19 were significantly younger and had higher stroke severity scores. They were more likely to experience thromboembolic and respiratory complications and in-hospital mortality compared with matched controls.

Asymptomatic Females Are at Higher Risk for Perioperative TIA/Stroke and Males Are at Higher Risk for Long-Term Mortality after Carotid Artery Stenting: A Vascular Quality Initiative Analysis.

The study aims to review the sex differences with respect to transient ischemic attack (TIA)/stroke and death in the perioperative period and on long-term follow-up among asymptomatic patients treated with carotid stenting (CAS) in the vascular quality initiative (VQI). All cases reported to VQI of asymptomatic CAS (ACAS) patients were reviewed. The primary end point was risk of TIA/stroke and death in the in-hospital perioperative period and in the long-term follow-up. The secondary end point was to evaluate predictors of in-hospital perioperative TIA/stroke and mortality on long-term follow-up after CAS. There were 22,079 CAS procedures captured from January 2005 to April 2019. There were 5,785 (62.7%) patients in the ACAS group. The rate of in-hospital TIA/stroke was higher in female patients (2.7 vs. 1.87%, p = 0.005) and the rate of death was not significant (0.03 vs. 0.07%, p = 0.66). On multivariable logistic regression analysis, prior/current smoking history (odds ratio = 0.58 [95% confidence interval or CI = 0.39-0.87]; p = 0.008) is a predictor of in-hospital TIA/stroke in females. The long-term all-cause mortality is significantly higher in male patients (26.9 vs. 15.7%, p < 0.001). On multivariable Cox-regression analysis, prior/current smoking history (hazard ratio or HR = 1.17 [95% CI = 1.01-1.34]; p = 0.03), coronary artery disease or CAD (HR = 1.15 [95% CI = 1.03-1.28]; p = 0.009), chronic obstructive pulmonary disease or COPD (HR = 1.73 [95% CI = 1.55-1.93]; p < 0.001), threat to life American Society of Anesthesiologists (ASA) class (HR = 2.3 [95% CI = 1.43-3.70]; p = 0.0006), moribund ASA class (HR = 5.66 [95% CI = 2.24-14.29]; p = 0.0003), and low hemoglobin levels (HR = 0.84 [95% CI = 0.82-0.86]; p < 0.001) are the predictors of long-term mortality. In asymptomatic carotid disease patients, women had higher rates of in-hospital perioperative TIA/stroke and a predictor of TIA/stroke is a prior/current history of smoking. Meanwhile, long-term all-cause mortality is higher for male patients compared with their female counterparts. Predictors of long-term mortality are prior/current smoking history, CAD, COPD, higher ASA classification of physical status, and low hemoglobin level. These data should be considered prior to offering CAS to asymptomatic female and male patients and careful risks versus benefits discussion should be offered to each individual patient.

Extracranial-Intracranial Bypass for Moyamoya Disease: The Influence of Racial and Socioeconomic Disparities on Outcomes - A National Inpatient Sample Analysis.

BACKGROUND: Extracranial-intracranial (EC-IC) bypass is an established therapeutic option for Moyamoya disease (MMD). However, little is known about the effects of racial and ethnic disparities on outcomes. This study assessed trends in EC-IC bypass outcomes among MMD patients stratified by race and ethnicity. METHODS: Utilizing the US National Inpatient Sample, we identified MMD patients undergoing EC-IC bypass between 2002 and 2020. Demographic and hospital-level data were collected. Multivariable analysis was conducted to identify independent factors associated with outcomes. Trend analysis was performed using piecewise joinpoint regression. RESULTS: Out of 14,062 patients with MMD, 1771 underwent EC-IC bypass. Of these, 60.59% were White, 17.56% were Black, 12.36% were Asians, 8.47% were Hispanic, and 1.02% were Native Americans. Nonhome discharge was noted in 21.7% of cases, with a 6.7% death and 3.8% postoperative neurologic complications rates. EC-IC bypass was more commonly performed in Native Americans (23.38%) and Asians (17.76%). Hispanics had the longest mean length of stay (8.4 days) and lower odds of nonhome discharge compared to Whites (odds ratio: 0.64; 95% confidence interval: 0.40-1.03; P = 0.04). Patients with Medicaid, private insurance, self-payers, and insurance paid by other governments had lower odds of nonhome discharge than those with Medicare. CONCLUSION: This study highlights racial and socioeconomic disparities in EC-IC bypass for patients with MMD. Despite these disparities, we did not find any significant difference in the quality of care. Addressing these disparities is essential for optimizing MMD outcomes.

Mesenchymal Stem Cell Therapy in Acute Intracerebral Hemorrhage: A Dose-Escalation Safety and Tolerability Trial.

BACKGROUND: We conducted a preliminary phase I, dose-escalating, safety, and tolerability trial in the population of patients with acute intracerebral hemorrhage (ICH) by using human allogeneic bone marrow-derived mesenchymal stem/stromal cells. METHODS: Eligibility criteria included nontraumatic supratentorial hematoma less than 60 mL and Glasgow Coma Scale score greater than 5. All patients were monitored in the neurosciences intensive care unit for safety and tolerability of mesenchymal stem/stromal cell infusion and adverse events. We also explored the use of cytokines as biomarkers to assess responsiveness to the cell therapy. We screened 140 patients, enrolling 9 who met eligibility criteria into three dose groups: 0.5 million cells/kg, 1 million cells/kg, and 2 million cells/kg. RESULTS: Intravenous administration of allogeneic bone marrow-derived mesenchymal stem/stromal cells to treat patients with acute ICH is feasible and safe. CONCLUSIONS: Future larger randomized, placebo-controlled ICH studies are necessary to validate this study and establish the effectiveness of this therapeutic approach in the treatment of patients with ICH.

Artificial intelligence and machine learning in aneurysmal subarachnoid hemorrhage: Future promises, perils, and practicalities.

INTRODUCTION: Aneurysmal subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke with thirty-day mortality as high as 40%. Given the expansion of Machine Learning (ML) and Artificial intelligence (AI) methods in health care, SAH patients desperately need an integrated AI system that detects, segments, and supports clinical decisions based on presentation and severity. OBJECTIVES: This review aims to synthesize the current state of the art of AI and ML tools for the management of SAH patients alongside providing an up-to-date account of future horizons in patient care. METHODS: We performed a systematic review through various databases such as Cochrane Central Register of Controlled Trials, MEDLINE, Scopus, Cochrane Database of Systematic Reviews, and Embase. RESULTS: A total of 507 articles were identified. Following extensive revision, only 21 articles were relevant. Two studies reported improved mortality prediction using Glasgow Coma Scale and biomarkers such as Neutrophil to Lymphocyte Ratio and glucose. One study reported that ffANN is equal to the SAHIT and VASOGRADE scores. One study reported that metabolic biomarkers Ornithine, Symmetric Dimethylarginine, and Dimethylguanidine Valeric acid were associated with poor outcomes. Nine studies reported improved prediction of complications and reduction in latency until intervention using clinical scores and imaging. Four studies reported accurate prediction of aneurysmal rupture based on size, shape, and CNN. One study reported AI-assisted Robotic Transcranial Doppler as a substitute for clinicians. CONCLUSION: AI/ML technologies possess tremendous potential in accelerating SAH systems-of-care. Keeping abreast of developments is vital in advancing timely interventions for critical diseases.

Safety and efficacy of the pipeline embolization device for treatment of small vs. large aneurysms: a systematic review and meta-analysis.

Flow diversion with the pipeline embolization device (PED) is increasingly used to treat intracranial aneurysms with high obliteration rates and low morbidity. However, long-term (≥ 1 year) angiographic and clinical outcomes still require further investigation. The aim of this study was to compare the occlusion and complication rates for small (< 10 mm) versus large (10-25 mm) aneurysms at long-term following treatment with PED. A systematic review and meta-analysis were performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We conducted a comprehensive search of English language databases including Ovid MEDLINE and Epub Ahead of Print, In-Process, and Daily, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. Our studies included a minimum of 10 patients treated with PED for small vs. large aneurysms and with at least 12 months of follow-up. The primary safety endpoint was the rate of clinical complications measured by the occurrence of symptomatic stroke (confirmed clinically and radiographically), intracranial hemorrhage, or aneurysmal rupture. The primary efficacy endpoint was the complete aneurysm occlusion rate. Our analysis included 19 studies with 1277 patients and 1493 aneurysms. Of those, 1378 aneurysms met our inclusion criteria. The mean age was 53.9 years, and most aneurysms were small (89.75%; N = 1340) in women (79.1%; N = 1010). The long-term occlusion rate was 73% (95%, CI 65 to 80%) in small compared to 84% (95%, CI 76 to 90%) in large aneurysms (p < 0.01). The symptomatic thromboembolic complication rate was 5% (95%, CI 3 to 9%) in small compared to 7% (95%, CI 4 to 13%) in large aneurysms (p = 0.01). The rupture rate was 2% vs. 4% (p = 0.92), and the rate of intracranial hemorrhage was 2% vs. 4% (p = 0.96) for small vs. large aneurysms, respectively; however, these differences were not statistically significant. The long-term occlusion rate after PED treatment is higher in large vs. small aneurysms. Symptomatic thromboembolic rates with stroke are also higher in large vs. small aneurysms. The difference in the rates of aneurysm rupture and intracranial hemorrhage was insignificant. Although the PED seems a safe and effective treatment for small and large aneurysms, further studies are required to clarify how occlusion rate and morbidity are affected by aneurysm size.

Percutaneous Closure Device for the Carotid artery: An integrated review and design analysis.

Endovascular thrombectomies (EVTs) are the current standard of care therapy for treating acute ischemic strokes. While access through the femoral or radial arteries is routine, up to 20% of EVTs through these sites are unable to access the cerebral vasculature on the first pass. These shortcomings are commonly due to tortuous vasculature, atherosclerotic arteries, and type III aortic arch, seen especially in the elderly population. Recent studies have shown the benefits of accessing the cerebral vasculature through a percutaneous direct carotid puncture (DCP), which can reduce the time of the procedure by half. However, current vascular closure devices (VCDs) designed for the femoral artery are not suited to close the carotid artery due to the anatomical differences. This unmet clinical need further limits a DCP approach. Thus, to foster safe adoption of this potential approach, a VCD designed specifically for the carotid artery is needed. In this review, we outline the major biomechanical properties and shortcomings of current VCDs and propose the requirements necessary to effectively design and develop a carotid closure device.

Greater burden of white matter lesions and silent infarcts ipsilateral to carotid stenosis.

OBJECTIVES: Carotid stenosis may cause silent cerebrovascular disease (CVD) through atheroembolism and hypoperfusion. If so, revascularization may slow progression of silent CVD. We aimed to compare the presence and severity of silent CVD to the degree of carotid bifurcation stenosis by cerebral hemisphere. MATERIALS AND METHODS: Patients age ≥40 years with carotid stenosis >50% by carotid ultrasound who underwent MRI brain from 2011-2015 at Mayo Clinic were included. Severity of carotid stenosis was classified by carotid duplex ultrasound as 50-69% (moderate), 70-99% (severe), or occluded. White matter lesion (WML) volume was quantified using an automated deep-learning algorithm applied to axial T2 FLAIR images. Differences in WML volume and prevalent silent infarcts were compared across hemispheres and severity of carotid stenosis. RESULTS: Of the 183 patients, mean age was 71±10 years, and 39.3% were female. Moderate stenosis was present in 35.5%, severe stenosis in 46.5% and occlusion in 18.0%. Patients with carotid stenosis had greater WML volume ipsilateral to the side of carotid stenosis than the contralateral side (mean difference, 0.42±0.21cc, p=0.046). Higher degrees of stenosis were associated with greater hemispheric difference in WML volume (moderate vs. severe; 0.16±0.27cc vs 0.74±0.31cc, p=0.009). Prevalence of silent infarct was 23.5% and was greater on the side of carotid stenosis than the contralateral side (hemispheric difference 8.8%±3.2%, p=0.006). Higher degrees of stenosis were associated with higher burden of silent infarcts (moderate vs severe, 10.8% vs 31.8%; p=0.002). CONCLUSIONS: WML and silent infarcts were greater on the side of severe carotid stenosis.

Flow diversion using the Pipeline embolization device for intracranial and extracranial pseudoaneurysms: a systematic review and meta-analysis of the literature.

OBJECTIVE: Pseudoaneurysms (PSAs) are complex vascular lesions. Flow diversion has been proposed as an alternative treatment to parent artery occlusion that preserves laminar flow. The authors of the present study investigated the safety and short-term (< 1 year) and long-term (≥ 1 year) aneurysm occlusion rates following the treatment of intracranial and extracranial PSAs using the Pipeline embolization device (PED). METHODS: An electronic database search for full-text English-language articles in Ovid MEDLINE and Epub Ahead of Print, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus was conducted following the PRISMA guidelines. Studies of any design including at least 4 patients with intracranial or extracranial PSAs treated using a PED were included in this analysis. The primary outcome of interest was the rate of peri- and postprocedural complications. Secondarily, the authors analyzed the incidence of complete aneurysm occlusion. RESULTS: A total of 90 patients with 96 PSAs across 9 studies were included. The mean age was 38.2 (SD 15.14) years, and 37.8% of the patients were women. The mean PSA size was 4.9 mm. Most PSAs were unruptured, and the most common etiology was trauma (n = 32, 35.5%), followed by spontaneous formation (n = 21, 23.3%) and iatrogenic injury (n = 19, 21.1%). Among the 51 (53.1%) intracranial and 45 (46.9%) extracranial PSAs were 19 (19.8%) dissecting PSAs. Sixty-six (77.6%) PSAs were in the internal carotid artery and 10 (11.8%) in the vertebral artery. Thirty-three (34.4%) PSAs were treated with ≥ 2 devices, and 8 (8.3%) underwent adjunctive coiling. The mean clinical and angiographic follow-up durations were 10.7 and 12.9 months, respectively. The short-term (< 1 year) and long-term (≥ 1 year) complete occlusion rates were 79% (95% CI 66%-88%, p = 0.82) and 84% (95% CI 70%-92%, p = 0.95), respectively. Complication rates were 8% for iatrogenic dissection (95% CI 3%-16%, p = 0.94), 10% for silent thromboembolism (95% CI 5%-21%, p = 0.77), and 12% for symptomatic thromboembolism (95% CI 6%-23%, p = 0.48). No treatment-related hemorrhage was observed. The overall mortality rate at the last follow-up was 14%. CONCLUSIONS: The complete occlusion rate for PSAs treated with the PED was high and increased over time. Although postprocedural complications and mortality were not insignificant, flow diversion represents a reasonably safe option for managing these complex lesions.

Absence of the torcular, review of venous sinus anatomy, and the simplified dural sinus classification.

BACKGROUND: Classically, the torcular Herophili is described as the symmetric junction between the superior sagittal sinus (SSS), transverse sinuses (TSs), and straight sinus (SS). However, finding this pattern in practice is not standard. Anatomical variations are common, and different drainage patterns should be expected. Existing literature proposes highly detailed descriptions and classifications of this region. Still, a simplified and practical categorization is not available. METHODS: We present an anatomical finding of the torcular Herophili discovered on a cadaveric dissection. Then, we conducted a retrospective study examining the 100 most recent cranial magnetic resonance venographies (MRVs) from the Mayo Clinic, labeling them with a new proposed dural sinus classification system. Images were initially classified by two authors and further validated by a board-certified neurosurgeon and a board-certified neuroradiologist from our institution. To measure consistency in image identification, two additional international neurosurgeons were asked to classify a subset of the same MRV images, and their answers were compared. RESULTS: Of the MRV cohort, 33 patients were male and 67 were female. Their ages ranged from 18 to 86 years, with a mean of 47.35 years and a median of 49 years. Upon examination, 53 patients presented as confluent (53%), 9 as SSS divergent (9%), 25 as SS divergent (25%), 11 as circular (11%), and 2 as trifurcated (2%). The inter-rater reliability ranked very good; agreement between the two neurosurgeons was 83% (κ = 0.830, p < 0.0005). CONCLUSION: The confluence of the venous sinuses is a highly variable anatomical area that is rarely evaluated with neuroimaging before surgery. The classic textbook configuration is not the rule. Using a simplified classification system may increase awareness and hopefully patient safety by preparing the physician for anatomical variations that they will encounter in a surgical or clinical scenario.