Predictors of aneurysmal occlusion following intracranial aneurysms treatment with pipeline embolization device.

PURPOSE: Pipeline embolization device (PED) is thought to induce aneurysmal occlusion through diversion of flow away from the aneurysmal sac with subsequent thrombosis and endothelialization. The impact of different factors especially hypertension (HTN)-a known predisposing factor to hypercoagulability and altered endothelial function-on aneurysmal occlusion after flow diversion has not been studied. We sought to determine predictors of aneurysmal occlusion following PED treatment focusing on impact of blood pressure. METHODS: Database of patients with cerebral aneurysms treated with PED from 2013 to 2019 at our institution was retrospectively reviewed. Patients were defined as hypertensive if (1) they had a documented history of HTN requiring anti-HTN medications or (2) average systolic blood pressure on three measurements was > 130 mmHg. The primary outcome was aneurysm occlusion status at the last imaging follow-up. Multivariable logistic regression model was constructed to assess the effect of HTN on occlusion, controlling for age, smoking, aneurysmal size, fusiform morphology, posterior circulation location, and incorporated branches. RESULTS: A total of 331 aneurysms in 294 patients were identified for this analysis. The mean age was 59 years (79.9% female). Fifty-five percent of the cohort were classified as hypertensive. When controlling for other potential confounders, hypertensive patients trended toward higher odds of achieving complete occlusion compared to non-hypertensive patients (OR = 2.05; 95% CI = 0.99-4.25; p = 0.052). Meanwhile, age (OR = 0.91; 95% CI = 0.88-0.95; p < 0.001) and an incorporated branch into an aneurysm (OR = 0.22; 95% CI = 0.08-0.58; p < 0.002) were associated with decreased odds for complete aneurysmal occlusion. CONCLUSION: Hypertensive patients show a trend toward higher odds of achieving complete occlusion when controlling for potential confounders. The HTN-induced hypercoagulable state, enhanced endothelial activation, and altered extracellular matrix regulation might be the contributing factors. Further research is warranted to explore clinical implications of these findings.

Cost Comparison for Open Surgery versus Middle Meningeal Artery Embolization in Patients with Chronic Subdural Hematomas: A Propensity Score-Matched Analysis.

BACKGROUND: Chronic subdural hematoma (cSDH) can be treated with conventional surgery or middle meningeal artery embolization (MMAE). The cost profiles of open surgery versus MMAE have never been studied. Therefore, we sought to compare the costs of surgical and MMAE treatment of cSDH. METHODS: Patients treated with open surgery (2006-2019) and MMAE (2018-2020) were identified from the institutional database. Propensity score matching analysis was used to assemble a balanced group of subjects. Detailed hospitalization costs in each group were collected and compared. RESULTS: A total of 341 conventionally treated and 52 MMAE cases were identified. After propensity score matching, 33 patients were included in each group, for a total of 66 patients for analysis. Direct procedural cost was significantly greater in the MMAE group compared with the open surgery group ($38,255 ± $11,859 vs. $11,206 ± $7888; P < 0.001). Medication cost also was greater in the MMAE group ($6888 ± $6525 vs. $4291 ± $3547; P = 0.048). No significant difference was found in costs for intensive care unit care, pharmacy, therapy, laboratory values, and the emergency department. Imaging costs and other miscellaneous costs (e.g., wound care, preoperative, and postanesthesia care unit) were greater in the open surgery group (P < 0.05). Total hospitalization cost was not significantly different between the 2 groups ($60,598 ± 61,315 vs. $71,569 ± $37,813 for open surgery and MMAE respectively, P = 0.385). No significant differences in number of follow ups or total costs for follow up were found (P > 0.05). CONCLUSIONS: Open surgery and MMAE offer an overall equivalent cost-profile for cSDH treatment when matching for potential cost confounders. Direct procedural costs are greater in MMAE; however, total hospitalization costs and follow up costs are not significantly different.

Middle meningeal artery: An effective pathway for achieving complete obliteration following transarterial Ethylene Vinyl Copolymer (Onyx) embolization of dural arteriovenous fistulas.

OBJECTIVE: Transarterial Onyx embolization is the mainstay of intracranial non-cavernous dural arteriovenous fistulas (dAVFs) treatment. Although the dural arterial supply varies depending on the location, the impact of arterial access on treatment outcomes has remained unclear. The aim of this study was to characterize factors as sociated with complete obliteration following transarterial Onyx embolization, with a special focus on arterial access routes and dAVF location. METHODS: A retrospective analysis of the patients who underwent transarterial Onyx embolization for intracranial dAVFs at two academic institutions was performed. Patients with angiographic follow-up were considered eligible to investigate the impact of the arterial access on achieving complete obliteration. RESULTS: Sixty-eight patients underwent transarterial Onyx embolization of intracranial dAVFs. Complete obliteration was achieved in 65% of all treated patients and in 75% of those with cortical venous reflux. Multivariable analysis identified middle meningeal artery (MMA) access to be a significant independent predictive factor for complete obliteration (OR, 2.32; 95% CI, 1.06-5.06; p=0.034). Subgroup analysis showed that supratentorial and lateral cerebellar convexity dAVFs (OR, 5.72, 95% CI, 1.89-17.33, p=0.002), and Borden type III classification at pre-treatment (OR, 3.13, 95% CI, 1.05- 9.35, p=0.041), were independent predictive factors for complete obliteration following embolization through the MMA. CONCLUSIONS: MMA access is an independent predictive factor for complete obliteration following transarterial Onyx embolization for intracranial non-cavernous dAVFs. It is particularly effective for supratentorial and lateral cerebellar convexity dAVFs and those that are Borden type III.

Asymptomatic Moyamoya Disease in a North American Adult Cohort.

OBJECTIVE: The natural history of asymptomatic adult moyamoya disease (MMD) is unclear, and the benefit of treatment remains controversial. This study aimed to investigate the natural history of asymptomatic MMD in a North American cohort and to evaluate risk factors associated with and the effects of treatment on disease progression. METHODS: Medical records from 3 institutions of consecutive adult patients with MMD diagnosed between 1984 and 2018 were retrospectively reviewed. Patients with unilateral or bilateral asymptomatic MMD were evaluated for subsequent development of infarction or hemorrhage. Multivariate Cox proportional hazards regression assessed risk factors associated with infarction or hemorrhage, adjusting for age, sex, race, initial Suzuki grade, hypertension, hyperlipidemia, diabetes, obesity, presence of aneurysms, smoking status, aspirin, and statin use at diagnosis. RESULTS: We identified 106 hemispheres with asymptomatic MMD in 97 patients with mean 5.1 years (interquartile range, 1.0-7.9 years) of follow-up. Of 106 hemispheres, 59 were treated medically, and 47 were treated with revascularization with direct or indirect bypasses. The medical and surgical cohorts had a 1.9% and 1.3% annual rate of radiographic infarction or hemorrhage per hemisphere, respectively. Cox regression for radiographic events, including early postoperative events, showed no significant difference between the treatment groups (adjusted hazard ratio 0.34 [95% confidence interval 0.05-2.5]). CONCLUSIONS: We found an overall 1.7% annual rate of radiographic infarction or hemorrhage in asymptomatic MMD hemispheres. Although we did not find a benefit to surgical treatment within the study period, asymptomatic patients with expected long-term survival may benefit from surgery given the sustained long-term benefits after surgery despite an initial postoperative risk.

Repeat Flow Diversion for Cerebral Aneurysms Failing Prior Flow Diversion: Safety and Feasibility From Multicenter Experience.

BACKGROUND: Aneurysmal persistence after flow diversion (FD) occurs in 5% to 25% of aneurysms, which may necessitate retreatment. There are limited data on safety/efficacy of repeat FD-a frequently utilized strategy in such cases. METHODS: A series of consecutive patients undergoing FD retreatment from 15 centers were reviewed (2011-2019), with inclusion criteria of repeat FD for the same aneurysm at least 6 months after initial treatment, with minimum of 6 months post-retreatment imaging. The primary outcome was aneurysmal occlusion, and secondary outcome was safety. A multivariable logistic regression model was constructed to identify predictors of incomplete occlusion (90%-99% and <90% occlusion) versus complete occlusion (100%) after retreatment. RESULTS: Ninety-five patients (median age, 57 years; 81% women) harboring 95 aneurysms underwent 198 treatment procedures. Majority of aneurysms were unruptured (87.4%), saccular (74.7%), and located in the internal carotid artery (79%; median size, 9 mm). Median elapsed time between the first and second treatment was 12.2 months. Last available follow-up was at median 12.8 months after retreatment, and median 30.6 months after the initial treatment, showing complete occlusion in 46.2% and near-complete occlusion (90%-99%) in 20.4% of aneurysms. There was no difference in ischemic complications following initial treatment and retreatment (4.2% versus 4.2%; P>0.99). On multivariable regression, fusiform morphology had higher nonocclusion odds after retreatment (odds ratio [OR], 7.2 [95% CI, 1.97-20.8]). Family history of aneurysms was associated with lower odds of nonocclusion (OR, 0.18 [95% CI, 0.04-0.78]). Likewise, positive smoking history was associated with lower odds of nonocclusion (OR, 0.29 [95% CI, 0.1-0.86]). History of hypertension trended toward incomplete occlusion (OR, 3.10 [95% CI, 0.98-6.3]), similar to incorporated branch into aneurysms (OR, 2.78 [95% CI, 0.98-6.8]). CONCLUSIONS: Repeat FD for persistent aneurysms carries a reasonable success/safety profile. Satisfactory occlusion (100% and 90%-99% occlusion) was encountered in two-thirds of patients, with similar complications between the initial and subsequent retreatments. Fusiform morphology was the strongest predictor of retreatment failure.

Surgical treatment of brainstem cavernous malformations: an international Delphi consensus.

OBJECTIVE: Indication for surgery in brainstem cavernous malformations (BSCMs) is based on many case series, few comparative studies, and no randomized controlled trials. The objective of this study was to seek consensus about surgical management aspects of BSCM. METHODS: A total of 29 experts were invited to participate in a multistep Delphi consensus process on the surgical treatment of BSCM. RESULTS: Twenty-two (76%) of 29 experts participated in the consensus. Qualitative analysis (content analysis) of an initial open-ended question survey resulted in 99 statements regarding surgical treatment of BSCM. By using a multistep survey with 100% participation in each round, consensus was reached on 52 (53%) of 99 statements. These were grouped into 4 categories: 1) definitions and reporting standards (7/14, 50%); 2) general and patient-related aspects (11/16, 69%); 3) anatomical-, timing of surgery-, and BSCM-related aspects (22/37, 59%); and 4) clinical situation-based decision-making (12/32, 38%). Among other things, a consensus was reached for surgical timing, handling of associated developmental venous anomalies, handling of postoperative BSCM remnants, assessment of specific anatomical BSCM localizations, and treatment decisions in typical clinical BSCM scenarios. CONCLUSIONS: A summary of typical clinical scenarios and a catalog of various BSCM- and patient-related aspects that influence the surgical treatment decision have been defined, rated, and interpreted.

Sodium Variability and Probability of Vasospasm in Patients with Aneurysmal Subarachnoid Hemorrhage.

OBJECTIVES: Vasospasm is a well-known complication of aneurysmal subarachnoid hemorrhage (aSAH) that generally occurs 4-14 days post-hemorrhage. Based on American Heart Association guidelines, the current understanding is that hyponatremic episodes may lead to vasospasm. Therefore, we sought to determine the association between repeated serum sodium levels of aSAH patients and its relationship to radiographic vasospasm. MATERIALS AND METHODS: A single-center retrospective analysis from 2007-2016 was conducted of aSAH patients. Daily serum sodium levels were recorded up to day 14 post-admission. Hyponatremia was defined as a serum sodium value of < 135 mEq/L. We evaluated the relationship to radiologic vasospasm, neurologic deterioration, functional status at discharge, and mortality. A repeated measures analysis using a mixed-effect regression model was performed to assess the interindividual relationship between serum sodium trends and outcomes. RESULTS: A total of 271 aSAH patients were included. There were no significant differences in interindividual serum sodium values over time and occurrence of radiographic vasospasm, neurologic deterioration, functional, or mortality outcomes (p = .59, p = .42, p = .94, p = .99, respectively) using the mixed-effect regression model. However, overall mean serum sodium levels were significantly higher in patients who had neurologic deterioration, poor functional outcome (mRS 3-6), and mortality. CONCLUSIONS: Serum sodium level variations are not associated with subsequent development of cerebral vasospasm in aSAH patients. These findings indicate that serum sodium may not have an impact on vasospasm, and avoiding hypernatremia may provide a neurologic, functional and survival benefit.

Mechanical thrombectomy beyond the circle of Willis: efficacy and safety of different techniques for M2 occlusions.

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

Cost-Effectiveness Analytic Comparison of Neuroimaging Follow-Up Strategies After Pipeline Embolization Device Treatment of Unruptured Intracranial Aneurysms.

BACKGROUND: Flow diversion via a Pipeline embolization device (PED [Medtronic, Dublin, Ireland]) is one of the established modalities for the treatment of unruptured intracranial aneurysms that require a robust follow-up regimen. However, to date, no consensus has been reached regarding the optimal imaging modality and timing intervals for such a strategy. We studied the cost-effectiveness of different neuroimaging follow-up strategies after flow diversion with the PED. METHODS: A decision-analytical study using Markov modeling was performed to compare 5 commonly used multistep follow-up strategies with different combinations of digital subtraction angiography (DSA) and magnetic resonance angiography (MRA): 1) DSA at 6 months and MRA at 12 and 24 months; 2) DSA at 6, 12, and 24 months; 3) MRA at 6, 12, and 24 months; 4) DSA at 6 and 12 months and MRA at 24 months; and 5) DSA at 12 months and MRA at 24 months. The input parameters were mainly collected from the latest meta-analysis, and 1-way, 2-way, and probabilistic sensitivity analyses were conducted to assess the robustness of our model. RESULTS: Strategy 5, incorporating DSA at 12 months and MRA at 24 months, was the most cost-effective strategy for >99% of the 10,000 iterations in the probabilistic sensitivity analysis at a willingness-to-pay threshold of $100,000/quality-adjusted life-year. The result remained robust in the 1- and 2-way sensitivity analyses. CONCLUSIONS: Given the current data, delayed imaging follow-up at 1 year with DSA and 2 years with MRA after PED treatment of unruptured intracranial aneurysms is more cost-effective than early follow-up at 6 months.

Morphological changes in chronic subdural hematomas following upfront middle meningeal artery embolization: sequence, timing, and association with outcomes.

OBJECTIVE: Middle meningeal artery embolization (MMAE) is an increasingly utilized approach for the treatment of chronic subdural hematomas (CSDHs). The course of morphological progression of CSDHs following MMAE is poorly understood. Herein, the authors aimed to describe these morphological changes and assess their prognostic significance for the outcomes on follow-up. METHODS: A single-institution retrospective cohort study of CSDH cases treated by upfront MMAE, without prior or adjunctive surgical evacuation, was performed. Clinical outcomes, complications, and the need for rescue surgery on follow-up were recorded. Hematomas were categorized into 6 morphological subtypes. All baseline and follow-up head CT scans were assessed for CSDH structural appearance, density, and loculation. Changes in CSDH size were quantified via 3D reconstruction for volumetric measurement. RESULTS: Overall, 52 CSDHs in 45 patients treated with upfront MMAE were identified. Hematomas were followed for a mean of 92.9 days. Volume decreased by ≥ 50% in 79.6% of the CSDHs. The overall rescue surgery rate was 9.6%. A sequence of morphological changes after MMAE was identified. Hematomas that diverged from this sequence (5.4%) all progressed toward treatment failure and required rescue surgery. The CSDHs were categorized into early, intermediate, and late stages based on the baseline morphological appearance. Progression from early to intermediate and then to late stage took 12.7 and 30.0 days, respectively, on average. The volume of early/intermediate- and late-stage hematomas decreased by ≥ 50%, a mean of 78.2 and 47.6 days after MMAE, respectively. Early- and intermediate-stage hematomas showed a trend toward more favorable outcomes compared with late-stage hematomas. The density of homogeneous hypodense hematomas (HSDHs) transiently increased immediately after MMAE (p < 0.001). A marked decrease in density and volume 1 to 3 weeks after MMAE in HSDHs was detected, the lack of which indicated an eventual need for rescue surgery. In HSDHs, a baseline mean density of < 20 HU, and a lower density than baseline by 1 month post-MMAE were predictors of favorable outcomes. The baseline hematoma volume, axial thickness, midline shift, and loculation were not correlated with MMAE outcomes. Loculated, trabecular, and laminar hematomas, which are known to have unfavorable surgical outcomes, had MMAE outcomes similar to those of other "surgical" hematomas. CONCLUSIONS: The current study was the first to describe the nature, sequence, and timing of morphological changes of CSDHs after MMAE treatment and has identified structural features that can predict treatment outcomes.

The use of staples for external ventricular drain catheter fixation: A single-institution experience.

BACKGROUND: Sutures are conventionally used for external ventricular drain (EVD) catheter fixation, but staples are an appealing alternative as they are quicker and easier to learn. We report our institutional experience with EVD fixation techniques and the patterns of catheter fixation. METHODS: We conducted a retrospective review of all aneurysmal subarachnoid hemorrhage (aSAH) patients treated in a single US center between 2007 and 2017. RESULTS: Out of 307 patients, 217 patients (62.2% female, mean age 59.5 years) met inclusion criteria harboring 268 EVDs. Two main configurations were used for EVD catheter fixation; spiral-shaped EVDs in 139 (51.9%) cases and arciform (C-shaped) EVDs in 129 (48.1%) of the cases. 220 (82.1%) were secured with staples and 48 (17.9%) with sutures. The most common complication was obstruction (n = 43, 16.2%), followed by infections (n = 18, 6.8%). Catheter dislodgements occurred in 16 (5.9%) catheters and 61 (22.8%) required repositioning/replacement. EVD dislodgement rates did not differ between the staples and sutures group, or between the spiral and C-shaped EVDs (p = 0.5 and 0.93, respectively). No cases of catheter perforation by the staples were encountered in our cohort. CONCLUSION: Staples and sutures are equally valid and acceptable methods for EVD fixation with similar dislodgement rates. Scarce data exist in the literature regarding dislodgements, and further studies are needed to address its incidence and the best preventive strategies.

Middle Meningeal Artery Embolization Versus Conventional Treatment of Chronic Subdural Hematomas.

BACKGROUND: Middle meningeal artery (MMA) embolization is an emerging minimally invasive endovascular technique for chronic subdural hematoma (cSDH). Currently, limited literature exists on its safety and efficacy compared with conventional treatment (open-surgical-evacuation-only). OBJECTIVE: To compare MMA embolization to conventional treatment. METHODS: Retrospective analysis of patients with cSDHs treated with MMA embolization in a single center from 2018 to 2019 was performed. Comparisons were made with a historical conventional treatment cohort from 2006 to 2016. Propensity score matching analysis was used to assemble a balanced group of subjects. RESULTS: A total of 357 conventionally treated cSDH and 45 with MMA embolization were included. After balancing with propensity score matching, a total of 25 pairs of cSDH were analyzed. Comparing the embolization with the conventional treatment group yielded no significant differences in complications (4% vs 4%; P > .99), clinical improvement (82.6% vs 83.3%; P = .95), cSDH recurrence (4.3% vs 21.7%; P = .08), overall re-intervention rates (12% vs 24%; P = .26), modified Rankin scale >2 on last follow-up (17.4% vs 32%; P = .24), as well as mortality (0% vs 12%; P = .09). Radiographic improvement at last follow-up was significantly higher in the open surgery cohort (73.9% vs 95.6%; P = .04). However, there was a trend for lengthier last follow-up for the historical cohort (72 vs 104 d; P = .07). CONCLUSION: There was a trend for lower recurrence and mortality rates in the embolization era cohort. There were significantly higher radiological improvement rates on last follow-up in the surgical only cohort era. There were no significant differences in complications and clinical improvement.

Tortuosity Index Predicts Early Successful Reperfusion and Affects Functional Status After Thrombectomy for Stroke.

OBJECTIVE: The literature is scarce for studies evaluating the anatomy of cervical vessels in patients with stroke. We sought to investigate the effect of vessel tortuosity in procedural, angiographic, and functional outcomes in patients with acute ischemic stroke treated with mechanical thrombectomy (MT). METHODS: Patients with an emergent large vessel occlusion of the anterior circulation treated with MT between 2015 and 2020 were included. The tortuosity of the internal carotid artery was recorded as the tortuosity index (TI) using the following formula: [(actual/straight length-1) × 100). A multivariable regression was performed to assess procedural, angiographic, and functional outcomes based on the TI. RESULTS: A total of 212 patients were included. Median age was 72 years (interquartile range, 62-82 years); admission National Institutes of Health Stroke Scale score was 17 ± 6. Median TI was 7.9 (interquartile range, 3.7-19.7). A total of 127 patients (60%) had a TI <10. Early reperfusion (procedure time <60 minutes) was accomplished in 144 patients (67.9%). A multivariable analysis showed that patients with a TI <10 were more likely to achieve an early reperfusion (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.11-4.78; P = 0.025). A TI <10 was a predictor of successful reperfusion (OR, 2.0; CI, 1.05-3.93; P = 0.035) and an early reperfusion was the sole predictor of functional independence (most recent modified Rankin Scale score 0-2) (OR, 4.1; 95% CI, 1.62-10.53; adjusted P = 0.003). CONCLUSIONS: Patients with a TI <10 are significantly more likely to achieve early successful reperfusion after MT for the treatment of acute ischemic stroke.

Trends of Ruptured and Unruptured Aneurysms Treatment in the United States in Post-ISAT Era: A National Inpatient Sample Analysis.

Background The ISAT (International Subarachnoid Aneurysm Trial) has generated a paradigm shift towards endovascular treatment for intracranial aneurysms but remains unclear if this has led to a true reduction in the risk for aneurysmal subarachnoid hemorrhage (aSAH). We sought to study the association between the treatment burden of unruptured and ruptured aneurysms in the post-ISAT era. Methods and Results Admissions data from the National Inpatient Sample (2004-2014) were extracted, including patients with a primary diagnosis of aSAH or unruptured intracranial aneurysms treated by clipping or coiling. Within each year, this combined group was randomly matched to non-aneurysmal control group, based on age, sex, and Elixhauser comorbidity index. Multinomial regression was performed to calculate the relative risk ratio of undergoing treatment for either ruptured or unruptured aneurysms in comparison with the reference control group, adjusted for time. After adjusting for National Inpatient Sample sampling effects, 243 754 patients with aneurysm were identified, 174 580 (71.6%) were women; mean age, 55.4±13.2 years. A total of 121 882 (50.01%) patients were treated for unruptured aneurysms, 79 627 (65.3%) endovascularly and 42 256 (34.7%) surgically. A total of 121 872 (49.99%) patients underwent procedures for aSAH, 68 921 (56.6%) endovascular, and 52 951 (43.5%) surgically. Multinomial regression revealed a significant year-to-year decrease in aSAH procedures compared with the control group of non-aneurysmal hospitalizations (relative risk ratio, 0.963 per year; P<0.001), while there was no statistical significance for unruptured aneurysms procedures (relative risk ratio, 1.012 per year; P=0.35). Conclusions With each passing year, there is a significant decrease in relative risk ratio of undergoing treatment for aSAH, concomitant with a stable annual risk of undergoing treatment for unruptured intracranial aneurysms.

Automated Lateral Ventricular and Cranial Vault Volume Measurements in 13,851 Patients Using Deep Learning Algorithms.

BACKGROUND: No large dataset-derived standard has been established for normal or pathologic human cerebral ventricular and cranial vault volumes. Automated volumetric measurements could be used to assist in diagnosis and follow-up of hydrocephalus or craniofacial syndromes. In this work, we use deep learning algorithms to measure ventricular and cranial vault volumes in a large dataset of head computed tomography (CT) scans. METHODS: A cross-sectional dataset comprising 13,851 CT scans was used to deploy U-Net deep learning networks to segment and quantify lateral cerebral ventricular and cranial vault volumes in relation to age and sex. The models were validated against manual segmentations. Corresponding radiologic reports were annotated using a rule-based natural language processing framework to identify normal scans, cerebral atrophy, or hydrocephalus. RESULTS: U-Net models had high fidelity to manual segmentations for lateral ventricular and cranial vault volume measurements (Dice index, 0.878 and 0.983, respectively). The natural language processing identified 6239 (44.7%) normal radiologic reports, 1827 (13.1%) with cerebral atrophy, and 1185 (8.5%) with hydrocephalus. Age-based and sex-based reference tables with medians, 25th and 75th percentiles for scans classified as normal, atrophy, and hydrocephalus were constructed. The median lateral ventricular volume in normal scans was significantly smaller compared with hydrocephalus (15.7 vs. 82.0 mL; P < 0.001). CONCLUSIONS: This is the first study to measure lateral ventricular and cranial vault volumes in a large dataset, made possible with artificial intelligence. We provide a robust method to establish normal values for these volumes and a tool to report these on CT scans when evaluating for hydrocephalus.

Transvenous Coil Embolization of a Transverse-Sigmoid Sinus Dural Arteriovenous Fistula: 2-Dimensional Operative Video.

This case is a 66-yr-old woman with a 2-mo history of left-sided tinnitus. Workup with magnetic resonance angiography showed early opacification of the left sigmoid sinus and internal jugular vein as well as asymmetric and abundant opacification of the left external carotid artery branches, suspicious for a dural arteriovenous fistula (dAVF). Diagnosis was confirmed with cerebral angiography, consistent with a left-sided Cognard type I dAVF.1 Initial treatment attempt was made with transarterial 6% ethylene-vinyl alcohol copolymer (Onyx 18) embolization of feeders from the occipital and middle meningeal arteries. However, embolization was not curative and there was a recurrence of a highly bothersome tinnitus 3 wk following treatment. Angiography redemonstrated the transverse sinus dAVF with new recruitment arising from several feeders, including the left external carotid artery, middle meningeal artery, and superficial temporal artery, now Cognard type IIa. Definitive treatment through a transvenous coil embolization provided permanent obliteration of the fistula without recrudescence of symptoms on follow-up. In this video, the authors discuss the nuances of treating a dAVF via a transvenous embolization. Patient consent was given prior to the procedure, and consent and approval for this operative video were waived because of the retrospective nature of this manuscript and the anonymized video material.

Direct Transverse Sinus Cannulation for Coil Embolization of a Transverse-Sigmoid Sinus Dural Arteriovenous Fistula: 2-Dimensional Operative Video.

A 65-yr-old male presented 2 mo after an episode of acute-onset headache associated with altered mental status. Imaging workup with cerebral angiography revealed a Cognard type IV right-sided transverse-sigmoid junction dural arteriovenous fistula (dAVF). The patient was treated with endovascular embolization of several pedicles from the middle meningeal (MMA) and occipital arteries. Residual filling and cortical venous reflux were noted on follow-up imaging. Therefore, definitive treatment of the persistent fistula was offered with a combined open and endovascular embolization approach.1 This would provide direct access into the sinus followed by embolization of the fistula. In the accompanying video, we present the case in detail and provide a discussion of the rational and treatment nuances associated with this approach. Patient consent was given prior to the procedure and consent and approval for this operative video were waived due to the retrospective nature of this manuscript and the anonymized video material.

Utility of Pipeline embolization device for emergency recanalization of a dissecting carotid tonsillar loop: illustrative cases.

BACKGROUND: Cervical arterial tortuosity is not uncommon in patients with spontaneous carotid artery dissections (CADs), but the tortuosity often precludes endovascular stent reconstruction. The authors report 2 cases of emergency recanalization of a carotid tonsillar loop dissection using a Pipeline embolization device (PED). OBSERVATIONS: Two patients presented with symptomatic CAD involving tonsillar looping of the cervical internal carotid artery (ICA). Although the tonsillar loop prevented navigation of the carotid and peripheral stent delivery system, a PED was easily navigated and successfully deployed, resulting in successful recanalization of a looped ICA. LESSONS: Emergency recanalization of a cervical CAD using a PED is a feasible alternative for treating a cervical CAD associated with tonsillar loops.