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.

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.

Pipeline Embolization Device Versus Stent-Assisted Coiling for Intracranial Aneurysm Treatment: A Retrospective Propensity Score-Matched Study

BACKGROUND

Pipeline embolization device (PED; Medtronic) and stent-assisted coiling (SAC) are established modalities for treatment of intracranial aneurysms.

OBJECTIVE

To comparatively assess the efficacy of these techniques.

METHODS

We conducted a retrospective analysis of patients with aneurysms treated at our institution with either PED from 2013 to 2017 or SAC from 2009 to 2015. All large (>10 mm), ruptured, fusiform, anterior communicating artery, posterior circulation aneurysms, and patients with no available follow-up imaging were eliminated before running the propensity score matching (PSM). Patients were matched using nearest neighbor controlling for: age, gender, smoking, exact location, maximal diameter, and presence of multiple aneurysms. Total hospital costs for equipment and implants were calculated from procedure product and hospital billing records, and compared between the propensity-matched pairs.

RESULTS

Out of 165 patients harboring 202 aneurysms; 170 (84.2%) were treated with the PED, and 32 (15.8%) were treated using SAC. PSM resulted in 23 matched pairs; with significantly longer follow up in the SAC group (mean 29.8 vs 14.1 mo; P = .0002). Complete occlusion rates were not different (82.6 vs 87%; P = .68), with no difference between the groups for modified Rankin Scale on last clinical follow-up, procedural complications or retreatment rates. Average total costs calculated from the hospital records, including equipment and implants, were not different between propensity-score matched pairs (P = .48).

CONCLUSION

PED placement and SAC offer equally efficacious occlusion rates, functional outcomes, procedural complication rates, and cost profiles for small unruptured anterior circulation saccular aneurysms which do not involve the anterior communicating artery.

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.

Evaluating the Readability of Online Patient Education Materials Related to Orthopedic Oncology

The internet is increasingly used to access patient education materials. The average American reading level has been found to be that of a 7th- to 8th-grade student, prompting the National Institutes of Health (NIH) and the American Medical Association (AMA) to advise that patient education materials be written between the 4th- to 6th-grade reading level. The purpose of this study was to evaluate the reading level of current patient education materials for the most common musculoskeletal oncological tumors. A Google search was performed with all location filters off to account for geographic variability for patient education materials related to 28 orthopedic primary or secondary tumors. All patient education articles from the first 10 website hits for each tumor type were analyzed. Patient education materials from these websites were evaluated using 8 validated readability scales. Patient resources were found to be written at an average grade level nearly double the NIH and AMA recommendation. Patient education materials for soft tissue chondromas were written at the highest level (14.8±1.9), whereas education materials for chordomas (10.1±1.0) most closely approached national recommendations, despite still being written at a readability level nearly 4 grade levels higher than has been recommended. The Flesch Reading Ease assessment provided a mean score of 46.5±7.7, corresponding with a "difficult to read" result. Current patient education materials regarding oncological musculoskeletal-related patient education materials are written significantly above the recommended reading level. Further modification of these resources is warranted to ensure adequate comprehension and informed decision making in the clinical setting. [Orthopedics. 2021;44(1):38-42.].

Upfront middle meningeal artery embolization for treatment of chronic subdural hematomas in patients with or without midline shift

OBJECTIVES

There is limited data on upfront middle meningeal artery (MMA) embolization in the context of significant midline shift (MLS) (greater than 5mm) for the treatment of chronic subdural hematomas (cSDH). This study reports the temporal changes following MMA embolization as an upfront treatment of cSDH in patients with or without MLS and either mild, no symptoms or mild and stable neurological deficits.

METHODS

A retrospective series of patients with a cSDH from a single institution in the United States between 2018-2020 was conducted. Eligible patients were treated with upfront MMA embolization.

RESULTS

27 upfront MMA embolization procedures in 23 patients were included. Twelve patients had MLS of 5 millimeters or more (52%). The median maximal thickness at diagnosis was 18 mm [11-22]. The mean distance of MLS was 5 mm ±4. There were no procedural complications. The overall rescue surgery rate was 15%. A single rescue surgery secondary to an increase in hematoma thickness was required (4%). The temporal changes for both hematoma and MLS showed gradual improvement between 2 weeks and 4 weeks post-procedure. The average time-to-resolution of MLS was 46 days in patients with less than 5 mm MLS and 51 days in those with 5 mm or more.

CONCLUSION

Upfront MMA embolization for cSDH with a thickness up to 25 mm provides adequate symptom relief, stabilization and/or progressive resorption of the cSDH during follow-up in carefully selected asymptomatic or mildly symptomatic patients even in the presence of a MLS greater than 5 mm.

Ruptured Spinal Aneurysms: Diagnosis and Management Paradigms

BACKGROUND

Spinal aneurysms (SA) are rare neurovascular pathologies with an unclear natural history and management strategy. We review the clinical and radiologic manifestations, management, and outcome of patients who presented with spinal subarachnoid hemorrhage (SAH) secondary to ruptured spinal aneurysms over a 10-year period. We provide a literature review about this condition and its management.

METHODS

All patients diagnosed with nontraumatic spinal SAH were collected from a single-center prospectively maintained database of patients with SAH between January 2010 and January 2020. Patients diagnosed with spinal aneurysms were reviewed. For each patient, demographic data, clinical presentation, imaging findings, management strategies, and outcomes are reviewed and discussed.

RESULTS

Between January 2010 and January 2020, ten patients were diagnosed with nontraumatic spinal SAH (3 patients presented with isolated spinal SAH and 7 patients with concomitant spinal and posterior fossa SAH). Among those, 4 patients were found to have a spinal aneurysm as the cause of SAH. The aneurysms were located in the cervical regions in 3 patients (75%) and at the thoracic level in 1 patient. Two aneurysms (50%) involved the anterior spinal artery, and 2 aneurysms (50%) involved a radiculomedullary artery. One aneurysm was a flow-related aneurysm of the anterior spinal artery in the setting of bilateral vertebral artery occlusion and was treated by surgical clipping with good outcome. Three aneurysms were idiopathic pseudoaneurysms with a negative diagnostic evaluation for secondary causes. These pseudoaneurysms were treated conservatively; 2 patients did well and 1 patient passed away from severe intracranial vasospasm. Two aneurysms resolved on diagnostic angiogram, and 1 aneurysm was absent on initial angiogram and appeared on follow-up diagnostic imaging 3 months later.

CONCLUSIONS

Spinal aneurysms are rare neurovascular pathologies that should be considered in the setting of spinal and/or posterior fossa subarachnoid hemorrhage. Conservative treatment may be a potential safe alternative to interventional treatment. Before the initiation of surgical or endovascular treatment, spinal angiography should be repeated because of the potential for spontaneous resolution.

A Novel Parameter to Predict Supraclinoid Aneurysm Persistence After Flow Diversion with the Pipeline Embolization Device

BACKGROUND

Aneurysm recurrence after Pipeline Embolization Device (PED) placement can be caused by oversizing of the stent as well as poor wall apposition, both of which can lead to elongation. The objective of this study was to assess whether a novel parameter for measuring device elongation based on two-dimensional imaging could be predictive for persistent aneurysm filling after treatment with the PED.

METHODS

A retrospective cohort analysis was initially completed on 41 aneurysms from institution A, examining demographic, aneurysmal, and device measurements. Device measurements, including the ratio of the measured length to the nominal length (ML/NL) of the PED, were taken by reviewers blinded to the primary end point, which was aneurysm occlusion status on 6 month catheter angiogram. Findings were then externally validated against 30 aneurysms (supraclinoid only) from institution B.

RESULTS

Data from institution A showed 61% complete aneurysm occlusion at 6 months, and were lower for aneurysms in the supraclinoid region. For supraclinoid aneurysms alone, combined data from both institutions showed higher rates of nonocclusion with aneurysm neck size >4 mm (P = 0.008) and a trend toward significance in aneurysms with a branch vessel (P = 0.051). The mean ML/NL ratio was significantly larger in the nonoccluded group compared with the occluded group at both institution A (ratio, 1.37 versus 1.10; P < 0.001) and institution B (ratio, 1.36 vs. 1.11; P = 0.002).

CONCLUSIONS

Our data suggest that a novel parameter based on two-dimensional angiography may serve as a rapid technique to measure device elongation and predict occlusion of supraclinoid aneurysms after PED placement.

Cigarette smoking and risk of intracranial aneurysms in middle-aged women

BACKGROUND AND PURPOSE

We previously reported a single-centre study demonstrating that smoking confers a six-fold increased risk for having an unruptured intracranial aneurysm (UIA) in women aged between 30 and 60 years and this risk was higher if the patient had chronic hypertension. There are no data with greater generalisability evaluating this association. We aimed to validate our previous findings in women from a multicentre study.

METHODS

A multicentre case-control study on women aged between 30 and 60 years, that had magnetic resonance angiography (MRA) during the period 2016-2018. Cases were those with an incidental UIA, and these were matched to controls based on age and ethnicity. A multivariable conditional logistic regression was conducted to evaluate smoking status and hypertension differences between cases and controls.

RESULTS

From 545 eligible patients, 113 aneurysm patients were matched to 113 controls. The most common reason for imaging was due to chronic headaches in 62.5% of cases and 44.3% of controls. A positive smoking history was encountered in 57.5% of cases and in 37.2% of controls. A multivariable analysis demonstrated a significant association between positive smoking history (OR 3.7, 95%CI 1.61 to 8.50), hypertension (OR 3.16, 95% CI 1.17 to 8.52) and both factors combined with a diagnosis of an incidental UIA (OR 6.9, 95% CI 2.49 to 19.24).

CONCLUSIONS

Women aged between 30 and 60 years with a positive smoking history have a four-fold increased risk for having an UIA, and a seven-fold increased risk if they have underlying chronic hypertension. These findings indicate that women aged between 30 and 60 years with a positive smoking history might benefit from a screening recommendation.

Endosaccular Flow Disruption: A New Frontier in Endovascular Aneurysm Management

Flow modification has caused a paradigm shift in the management of intracranial aneurysms. Since the FDA approval of the Pipeline Embolization Device (Medtronic, Dublin, Ireland) in 2011, it has grown to become the modality of choice for a range of carefully selected lesions, previously not amenable to conventional endovascular techniques. While the vast majority of flow-diverting stents operate from within the parent artery (ie, endoluminal stents), providing a scaffold for endothelial cells growth at the aneurysmal neck while inducing intra-aneurysmal thrombosis, a smaller subset of endosaccular flow disruptors act from within the lesions themselves. To date, these devices have been used mostly in Europe, while only utilized on a trial basis in North America. To the best of our knowledge, there has been no dedicated review of these devices. We therefore sought to present a comprehensive review of currently available endosaccular flow disruptors along with high-resolution schematics, presented with up-to-date available literature discussing their technical indications, procedural safety, and reported outcomes.

The Pipeline Embolization Device: Changes in Practice and Reduction of Complications in the Treatment of Anterior Circulation Aneurysms in a Multicenter Cohort

BACKGROUND

The Pipeline Embolization Device (PED; Medtronic, Dublin, Ireland) has become an important tool for the treatment of cerebral aneurysms. Since FDA approval, there are ongoing efforts to increase aneurysm occlusion rates and reduce the incidence of complications.

OBJECTIVE

To assess aneurysm occlusion and complication rates over time.

METHODS

Retrospective analysis of consecutive anterior circulation aneurysms treated with a single PED between 2011 and 2016 at 3 academic institutions in the US was performed. Factors contributing to changes in aneurysm occlusion and complication rates over time were identified and evaluated.

RESULTS

A total of 284 procedures were performed on 321 anterior circulation aneurysms in 284 patients. At a median follow-up of 13 mo (mean 18 mo), complete or near complete occlusion (>90%) was achieved in 85.9% of aneurysms. There was no significant change in aneurysm occlusion rate or procedure length over time. Thromboembolic complication occurred in 8.1% of procedures, and there was a trend toward decreased incidence from 16.3% in 2011/2012 to 3.3% in 2016 (P = .14). Hemorrhagic complications significantly decreased from 8.2% in 2011/2012 to 0 to 1.0% in 2014-2016 (P = .1).

CONCLUSION

We report a notable drop in the rate of hemorrhagic and to a lesser extent thromboembolic complications with increased experience with PED in a multicenter cohort. Multiple factors are believed to contribute to this drop, including the evolved interpretation of platelet function testing, the switching of clopidogrel nonresponders to ticagrelor, and the reduced use of adjunctive coiling.

Aneurysmal subarachnoid hemorrhage in patients with migraine and tension headache: A cohort comparison study

Migraine headache is a common condition with an estimated lifetime prevalence of greater than 20%. While it is a well-established risk factor for cardiovascular disease and ischemic stroke, its association with subarachnoid hemorrhage is largely unexplored. We sought to compare the incidence of aneurysmal subarachnoid hemorrhage in a cohort of migraine patients with a cohort of patients with tension headache. A cohort comparison study utilizing the MarketScan insurance claims database compared patients diagnosed with migraine who were undergoing treatment with abortive or prophylactic pharmacotherapy (treatment cohort) and patients diagnosed with tension headache who had never been diagnosed with a migraine and who were naïve to migraine pharmacotherapy (control cohort). Patients with major pre-existing risk factors for aSAH were excluded from the study, and minor risk factors such as smoking status and hypertension were accounted for using coarsened exact matching (CEM) and subsequent cox proportional-hazards (CPH) regression. More than 679,000 patients (~125,000 treatment and ~ 550,000 control) with an average follow-up of more than three years were analyzed for aneurysmal subarachnoid hemorrhage. CPH regression on matched data showed that treated migraine patients had a significantly lower hazard of aneurysmal subarachnoid hemorrhage compared with tension headache patients (HR = 0.40, 95% CI: 0.19 - 0.86, p = 0.02). This large cohort comparison study, analyzing more than 679,000 patients, demonstrated that migraine patients undergoing pharmacologic treatment had a lower hazard of aneurysmal subarachnoid hemorrhage than patients diagnosed with tension headaches. Future work specifically focusing on migraine medications may identify the mechanisms underlying this association.

Women With First-Hand Tobacco Smoke Exposure Have a Higher Likelihood of Having an Unruptured Intracranial Aneurysm Than Nonsmokers: A Nested Case-Control Study

BACKGROUND

The prevalence of unruptured intracranial aneurysms (UIA) in females who smoke cigarettes and the association between smoking and hypertension with purely incidental UIAs have been unexplored.

OBJECTIVE

To obtain the prevalence of UIA among females and to assess the relationship between smoking and hypertension with a diagnosis of incidental UIAs.

METHODS

A nested case-control study from a cohort of female patients aged between 30 and 60 yr with a brain magnetic resonance angiography (MRA) between 2016 and 2018. Incidental UIAs were compared to patients with normal MRAs. Smoking was characterized as never or former/current smokers. A logistic regression was used to evaluate the association between smoking, hypertension, or both, with a diagnosis of incidental UIAs.

RESULTS

A total of 1977 patients had a brain MRA between 2016 and 2018. From 1572 nonsmoker patients, we encountered 30 with an UIA (prevalence: 1.9%). There were 405 patients with a positive smoking history, and 77 patients harbored an UIA (prevalence: 19%). Of 64 aneurysm patients and 130 random controls eligible for the case control, aneurysm patients were more likely to have a positive smoking history and hypertension compared with healthy controls (60% vs 18%, P ≤ .001; 44% vs 14%, P ≤ .001). A multivariable analysis demonstrated a significant association between a smoking history, hypertension, or both factors with an incidental UIA (odds ratio [OR] 5.8 CI 1.22-11.70; OR 3.8 CI 2.31-14.78; OR 12.6 CI 4.38-36.26; respectively).

CONCLUSION

Females who smoke cigarettes have a higher prevalence of UIAs than the general population. Smoking confers a higher risk for having a silent UIA, aggravated by hypertension. This population is an ideal target for potential screening.

The Reproducibility of Cerebrovascular Randomized Controlled Trials

BACKGROUND

Numerous randomized controlled trials (RCTs) relevant to the cerebrovascular field have been performed. The fragility index was recently developed to complement the P value and measure the robustness and reproducibility of clinical findings of RCTs.

OBJECTIVE

In this study, we evaluate the fragility index for key surgical and endovascular cerebrovascular RCTs and propose a novel RCT classification system based on the fragility index.

METHODS

Cerebrovascular RCTs reported between 2000 and 2018 were reviewed. Six key areas were specifically targeted in relation to stroke, carotid stenosis, cerebral aneurysms, and subarachnoid hemorrhage. The correlation between fragility index, number of patients lost to follow-up, and fragility quotient were evaluated to propose a classification system for the robustness of the studies.

RESULTS

A total of 20 RCTs that reported significant differences between both study groups in terms of the primary outcome were included. The median fragility index for the trials was 5.5. An additional 30 randomly selected RCTs were added to propose a classification system with high reliability. The difference between the number of patients lost to follow-up and fragility index inversely correlated with the fragility quotient and was used to divide the robustness of the RCTs into 3 classes reflecting the reproducibility of the trial.

CONCLUSIONS

Neurosurgeons and neurointerventionalists should exercise caution with interpreting the results of cerebrovascular RCTs, especially when the sample size and events numbers are small and there is a high number of patients who were lost to follow-up, as quantitatively identified using the proposed classification system.

Implications of the Collar Sign in Incompletely Occluded Aneurysms after Pipeline Embolization Device Implantation: A Follow-Up Study

BACKGROUND AND PURPOSE

The angiographic collar sign has been recently described in patients with incompletely occluded aneurysms after Pipeline Embolization Device implantation. The long-term implications of this sign are unknown. We report angiographic outcomes of patients with the collar sign with follow-up of up to 45 months and the implications of this angiographic finding.

MATERIALS AND METHODS

We performed a retrospective review of a prospectively maintained data base of patients who underwent Pipeline Embolization Device implantation for an intracranial aneurysm at our institution between January 2014 and December 2016. We included patients with a collar sign at the initial follow-up angiogram after Pipeline Embolization Device implantation.

RESULTS

A total of 198 patients with 285 aneurysms were screened for the collar sign on initial and subsequent follow-up angiograms. There were 226 aneurysms (79.3%) with complete occlusion at the first follow-up. Of 59 incompletely occluded aneurysms, 19 (32.2%) aneurysms in 17 patients were found to have a collar sign on the first angiographic follow-up (median, 6 months; range, 4.2-7.2). Ten (52.6%) aneurysms underwent retreatment with a second Pipeline Embolization Device, which resulted in aneurysm occlusion in 1 (10%) patient. There were only 3 (15.8%) aneurysms with complete occlusion at the last follow-up, 2 (10.5%) of which had a single Pipeline Embolization Device implantation and another single (5.3%) aneurysm with a second Pipeline Embolization Device implantation.

CONCLUSIONS

A collar sign on the initial angiogram after Pipeline Embolization Device placement is a predictor of poor aneurysm occlusion. Because the occlusion rates remain equally low regardless of retreatment in patients with a collar sign, radiologic follow-up may be more appropriate than retreatment.

The geology and geophysics of Kuiper Belt object (486958) Arrokoth

The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, is composed of primitive objects preserving information about Solar System formation. In January 2019, the New Horizons spacecraft flew past one of these objects, the 36-kilometer-long contact binary (486958) Arrokoth (provisional designation 2014 MU₆₉). Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters in diameter) within a radius of 8000 kilometers. Arrokoth has a lightly cratered, smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism.

Color, composition, and thermal environment of Kuiper Belt object (486958) Arrokoth

The outer Solar System object (486958) Arrokoth (provisional designation 2014 MU₆₉) has been largely undisturbed since its formation. We studied its surface composition using data collected by the New Horizons spacecraft. Methanol ice is present along with organic material, which may have formed through irradiation of simple molecules. Water ice was not detected. This composition indicates hydrogenation of carbon monoxide-rich ice and/or energetic processing of methane condensed on water ice grains in the cold, outer edge of the early Solar System. There are only small regional variations in color and spectra across the surface, which suggests that Arrokoth formed from a homogeneous or well-mixed reservoir of solids. Microwave thermal emission from the winter night side is consistent with a mean brightness temperature of 29 ± 5 kelvin.

Effect of Blood Pressure Variability During the Acute Period of Subarachnoid Hemorrhage on Functional Outcomes

BACKGROUND

The association of blood pressure variation with poor outcomes in aneurysmal subarachnoid hemorrhage (aSAH) is unknown.

OBJECTIVE

To evaluate the association of systolic blood pressure (SBP) variation and clinical outcomes in aSAH.

METHODS

We conducted a retrospective chart review of all aSAH patients treated at an academic institution between 2007 and 2016. Patient demographics, aSAH characteristics, and blood pressure observations for the first 24 h of admission in 4-h intervals were obtained. SBP variability metrics assessed were mean, standard deviation, maximum, minimum, peak, trough, coefficient of variation, and successive variation. The primary outcome was a composite of the modified Rankin scale as good (0-2) or poor (3-6) at last follow-up. Comparisons between outcome groups were performed. Logistic regression models for each significant SBP metric controlling for potential confounders were constructed.

RESULTS

The study population was 202 patients. The mean age was 57 yr; 66% were female. The median follow-up time was 18 mo; 57 (29%) patients had a poor outcome. Patients with poor outcomes had higher standard deviation (17.1 vs 14.7 mmHg, P = .01), peak (23.5 vs 20.0 mmHg, P = .02), trough (22.6 vs 19.2 mmHg, P &lt; .01), coefficient of variation (13.9 vs 11.8 mmHg, P &lt; .01), and lower minimum SBP (101.4 vs 108.4, P &lt; .01). The logistic regression showed that every 1-mmHg increase in the minimum SBP increased the odds of good outcomes (odds ratio = 1.03; 95% CI = 1.001-1.064; P = .04). Models including other SBP metrics were not significant.

CONCLUSION

Hypotension was found to be independently associated with poor outcomes in patients with aSAH.

The solar nebula origin of (486958) Arrokoth, a primordial contact binary in the Kuiper Belt

The New Horizons spacecraft's encounter with the cold classical Kuiper Belt object (486958) Arrokoth (provisional designation 2014 MU₆₉) revealed a contact-binary planetesimal. We investigated how Arrokoth formed and found that it is the product of a gentle, low-speed merger in the early Solar System. Its two lenticular lobes suggest low-velocity accumulation of numerous smaller planetesimals within a gravitationally collapsing cloud of solid particles. The geometric alignment of the lobes indicates that they were a co-orbiting binary that experienced angular momentum loss and subsequent merger, possibly because of dynamical friction and collisions within the cloud or later gas drag. Arrokoth's contact-binary shape was preserved by the benign dynamical and collisional environment of the cold classical Kuiper Belt and therefore informs the accretion processes that operated in the early Solar System.

Symptomatic Hemorrhage From Cerebral Cavernous Malformations: Evidence from a Cohort Study

OBJECTIVE

Patients with a cerebral cavernous malformation (CCM) can have intracranial hemorrhages ranging from insignificant and chronic microbleeds to life-threatening hemorrhage. Management decisions and patient counseling are based on a heterogeneous body of evidence. We sought to improve the literature by providing our results based on the standardized definitions and aimed to delineate differences in the symptomatic burden for CCMs, based on their anatomic location and presence of developmental venous anomalies. This evidence will aid in clinical decision making and patient counseling.

METHODS

A retrospective cohort analysis between 1990 and 2018 was performed, including patients with a diagnosis of a CCM. The primary outcome was acute symptomatic hemorrhages.

RESULTS

We identified 438 patients harboring 632 CCMs. Mean age at diagnosis was 50 years (standard deviation ±17 years). Median follow-up was 26 months (interquartile range, 7-72 hours). Multiple lesions were encountered in 64 patients (15%). An initial symptomatic presentation was observed in 64% of the patients. There were 438 supratentorial lesions (69%) and 194 infratentorial lesions (31%). A symptomatic hemorrhage was observed in 25% of the supratentorial lesions and 29% of the infratentorial lesions (P < 0.001). A linear mixed-effects regression model showed a significant difference in developing a symptomatic hemorrhage at diagnosis or follow-up between CCMs with an infratentorial location and those with a supratentorial location (odds ratio, 1.81; 95% confidence interval, 1.17-2.81; P = 0.008).

CONCLUSIONS

Infratentorial cavernous malformations are more likely to present with symptomatic hemorrhages at diagnosis or during follow-up when accounting for size differences between lesions.

Relationship between external ventricular drain clamp trials and ventriculoperitoneal shunt insertion following nontraumatic subarachnoid hemorrhage: a single-center study

OBJECTIVE

Currently, there is no established standard regarding the ideal number of external ventricular drain (EVD) clamp trials performed before ventriculoperitoneal (VP) shunt insertion following nontraumatic subarachnoid hemorrhage (SAH). In this study, the authors aimed to evaluate this relationship.

METHODS

A retrospective review of all patients presenting with SAH between July 2007 and December 2016 was performed. Patients with SAH who had received an EVD within the first 24 hours of hospital admission and had undergone at least 1 clamp trial prior to EVD removal were eligible for inclusion in the study. Patient demographics, clinical presentations, SAH etiologies and grades, clamp trial data, hospital lengths of stay, and functional outcomes were recorded.

RESULTS

One hundred fourteen patients with nontraumatic SAH complicated by posthemorrhagic hydrocephalus were included in the study. The median patient age was 57 years (range 28-90 years), with a male/female ratio of 1:1.7. A ruptured aneurysm was the underlying etiology of SAH in 79.8% of patients. A majority of patients (69.4%) had a Hunt and Hess grade III-V on admission. The median number of clamp trials performed was 2 (range 1-6). A VP shunt was required in 40.4% of patients. In those who underwent 2 and 3 clamp trials, 60% and 38.9%, respectively, did not require subsequent VP shunt placement.

CONCLUSIONS

Surgical placement of a VP shunt is associated with complications. Clamp trials are routinely performed before making the decision to insert a shunt. In the present study, the authors found that a significant percentage of patients passed their second and third clamp trials without requiring subsequent shunt insertion. These data support performing multiple clamp trials prior to shunt placement.

A Direct Aspiration First Pass Technique vs Standard Endovascular Therapy for Acute Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

The direct aspiration first pass technique (ADAPT) is a recent endovascular treatment for ischemic stroke due to large vessel occlusion that has been gaining popularity due to the rapidity of the technique and the potential for cost savings in comparison to standard thrombectomy methods such as stent retrievers. However, few studies have directly compared these 2.

OBJECTIVE

To compare ADAPT with stent retrievers for thrombectomy via systematic review and meta-analysis.

METHODS

Ovid Medline, PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, ACP Journal Club, and Database of Abstracts of Review of Effectiveness limited to English through September 2016 were systematically searched. Eligible studies included those in which patient cohorts underwent ADAPT for acute stroke. Recanalization efficiency, clinical outcomes, and complication rates of ADAPT were compared with the current standard of endovascular thrombectomy techniques.

RESULTS

Seventeen studies on ADAPT and 5 randomized controlled trials on endovascular therapy were included. ADAPT achieved higher rates of complete revascularisation (89.4% vs 71.7%, P < .001) but similar clinical outcomes compared to front-line endovascular therapy. Seventy-one point four percent of ADAPT cases were successfully recanalized with aspiration alone, and a trend towards reduced time from groin puncture to recanalization time was noted (44.77 vs 61.46 min, P = .088).

CONCLUSION

The pooled results are comparable with recent randomized studies that demonstrate the benefit of endovascular therapy over intra-arterial medical therapy. Future direct comparative studies and randomized trials are required to confirm the benefit of the ADAPT strategy compared to standard endovascular therapy for acute ischemic stroke.

A Cohort Comparison Analysis of Fixed Pressure Ventriculoperitoneal Shunt Valves With Programmable Valves for Hydrocephalus Following Nontraumatic Subarachnoid Hemorrhage

BACKGROUND

Hydrocephalus after nontraumatic subarachnoid hemorrhage (SAH) is a common sequela that may require the placement of ventriculoperitoneal shunts (VPS). Adjustable-pressure valves (APVs) are being widely used in this situation though more expensive than differential-pressure valves (DPVs).

OBJECTIVE

To compare outcomes between APV and DPV in SAH-induced hydrocephalus.

METHODS

We performed a retrospective chart review of patients with nontraumatic SAH who underwent VPS placement for the treatment of hydrocephalus after SAH, between July 2007 and December 2016. Patients were classified according to the type of valve (APV vs DPV). We evaluated factors that could predict the type of valve used, outcomes in VPS revision/replacement rate, and complications.

RESULTS

A total of 66 patients underwent VPS placement who were equally distributed into the 2 groups of valves. VPS failure with the need for revision/replacement occurred in 13 (19.7%) cases. Ten (30.3%) patients with DPV had a VPS failure, while 3 (9.1%) patients with an APV had a similar failure with the need for revision/replacement (P = .03). VPS placement before discharge during the initial hospitalization (P = .02) was statistically significant associated with the use of a DPV, while the reason of external ventricular drain (EVD) failure (P = .03) was associated with the use of an APV.

CONCLUSION

APVs had a lower rate of surgical revisions compared to DPVs. Early placement of VPS was associated with the use of a DPV. The need for EVD replacement due to EVD infection or malfunction was associated with higher rates of APV use.

Proposal of a follow-up imaging strategy following Pipeline flow diversion treatment of intracranial aneurysms

OBJECTIVE

There is currently no standardized follow-up imaging strategy for intracranial aneurysms treated with the Pipeline embolization device (PED). Here, the authors use follow-up imaging data for aneurysms treated with the PED to propose a standardizable follow-up imaging strategy.

METHODS

A retrospective review of all patients who underwent treatment for ruptured or unruptured intracranial aneurysms with the PED between March 2013 and March 2017 at 2 major academic institutions in the US was performed.

RESULTS

A total of 218 patients underwent treatment for 259 aneurysms with the PED and had undergone at least 1 follow-up imaging session to assess aneurysm occlusion status. There were 235 (90.7%) anterior and 24 posterior (9.3%) circulation aneurysms. On Kaplan-Meier analysis, the cumulative incidences of aneurysm occlusion at 6, 12, 18, and 24 months were 38.2%, 77.8%, 84.2%, and 85.1%, respectively. No differences in the cumulative incidence of aneurysm occlusion according to aneurysm location (p = 0.39) or aneurysm size (p = 0.81) were observed. A trend toward a decreased cumulative incidence of aneurysm occlusion in patients 70 years or older was observed (p = 0.088). No instances of aneurysm rupture after PED treatment or aneurysm recurrence after occlusion were noted. Sixteen (6.2%) aneurysms were re-treated with the PED; 11 of these had imaging follow-up data available, demonstrating occlusion in 3 (27.3%).

CONCLUSIONS

The authors propose a follow-up imaging strategy that incorporates 12-month digital subtraction angiography and 24-month MRA for patients younger than 70 years and single-session digital subtraction angiography at 12 months in patients 70 years or older. For recurrent or persistent aneurysms, re-treatment with the PED or use of an alternative treatment modality may be considered.

Neural Crest Cell Failure as Embryogenesis for Fusiform Aneurysm of the Anterior Communicating Artery: Case Report and Review of the Literature

BACKGROUND

Pure fusiform aneurysms of the anterior communicating artery (AcomA) are rare. We report a unique case of a patient with an AComA fusiform aneurysm in the setting of several unusual cranial neurocristopathies, including a hypoplastic internal carotid artery (ICA), persistent craniopharyngeal canal, transsphenoidal encephalocele, and ectopic, duplicated pituitary gland. We also review the literature on cranial base neurocristopathies and AComA fusiform aneurysms.

CASE DESCRIPTION

This 46-year-old patient had a history of short stature, osteoporosis, obesity, cleft lip, decreased libido, congenital left eye blindness, headaches, and chronic nasal congestion. Magnetic resonance imaging revealed a 25 × 25 × 33 mm heterogenous soft tissue mass with an ectopic pituitary gland extending transsphenoidally and a duplicated pituitary stalk. A hormone panel revealed undetectable insulin-like growth factor 1 and growth hormone, central hypogonadism, and elevated prolactin. Before presentation, computed tomography angiography (CTA) had revealed a congenitally hypoplastic right ICA and 4.7 × 10.7 mm fusiform aneurysm of the AComA. Digital subtraction angiography confirmed stable morphology after 9 years. Nonoperative management of aneurysm and cephalocele was elected, with repeat CTA in 1 year.

CONCLUSIONS

This case provides evidence that inherent arterial wall defects can contribute to fusiform aneurysm formation in the AComA. We propose that small AComA fusiform aneurysms without sclerotic or symptomatic features can be safely observed by describing the longest reported conservative management for this type of aneurysm. A high degree of suspicion for cerebrovascular anomalies should be maintained in patients who present with cranial neurocristopathy.

Initial results from the New Horizons exploration of 2014 MU69, a small Kuiper Belt object

The Kuiper Belt is a distant region of the outer Solar System. On 1 January 2019, the New Horizons spacecraft flew close to (486958) 2014 MU₆₉, a cold classical Kuiper Belt object approximately 30 kilometers in diameter. Such objects have never been substantially heated by the Sun and are therefore well preserved since their formation. We describe initial results from these encounter observations. MU₆₉ is a bilobed contact binary with a flattened shape, discrete geological units, and noticeable albedo heterogeneity. However, there is little surface color or compositional heterogeneity. No evidence for satellites, rings or other dust structures, a gas coma, or solar wind interactions was detected. MU₆₉'s origin appears consistent with pebble cloud collapse followed by a low-velocity merger of its two lobes.

Sigma-1 receptor antagonist PD144418 suppresses food reinforced operant responding in rats

Sigma-1 (σ1) receptors have been investigated for their involvement in learning, rewarding and motivational processes, particularly as it relates to substances of abuse. Few studies have examined the effects of σ1 receptor agonists and antagonists on the rewarding and motivational properties of natural reinforcers, such as food. Studies that have investigated σ1 receptor agonists and antagonists has produced conflicting results. σ1 receptor antagonist PD144418 has been found to produce a dose-dependent attenuation of locomotor activity induced by cocaine, and by itself, does not suppress basal locomotor activity in mice. However, its effects on reward and motivation as it relates to food are unknown. The present study examined the involvement of σ1 receptors in mediating the rewarding and motivational properties of food using an operant task. The results indicated that at the highest dose (10 μmol/kg), PD144418 significantly attenuated the number of active lever responses for chow pellets but did not decrease the number of active lever responses for sucrose pellets under a fixed ratio (FR2) schedule of reinforcement. However, under a progressive ratio (PR) reinforcement schedule, 10 μmol/kg of PD14418 significantly reduced the breakpoint, a measure indicative of effort or motivation, for both chow and sucrose pellets. When ad libitum chow or sucrose pellets were made freely available (i.e. no lever press required) inside the operant chamber, 10 μmol/kg, PD144418 did not have an effect on number of pellets consumed. These findings indicate that PD144418 reduces the motivational effort of a food reinforced behavior.

No differences in effectiveness and safety between pipeline embolization device and stent-assisted coiling for the treatment of communicating segment internal carotid artery aneurysms

BACKGROUND

Aneurysms arising from the communicating segment (C7) of the internal carotid artery (ICA) are one of the most frequent locations of intracranial aneurysms. Stent-assisted coiling (SAC) and flow diversion therapies are both endovascular strategies used for the treatment of ICA aneurysms occurring at the C7 segment.

OBJECTIVE

The aim of this study is to compare both methods' angiographic and functional outcomes, and procedural complications. To our knowledge, this is the first study to compare both modalities for aneurysms at this location.

METHODS

A retrospective review was performed of our prospectively collected database from 2008 until 2017 for patients treated with SAC and from 2013 until 2017 for patients treated with pipeline embolization devices (PEDs).

RESULTS

We identified 35 patients for this cohort with 38 aneurysms; 17 treated with SAC and 21 with PED. Mean age was 59 years, and 30 patients were female (86%). Complete occlusion at last follow-up occurred in 70.6% of patients in the SAC group and in 81% in the PED group (p = 0.45). Posterior communicating artery patency at last follow-up did not differ significantly between the two groups (94.1% vs 85.7%; p = 0.40). Good functional outcome at last follow-up (mRS 0-2) was achieved in 100% and 88.2% of patients, respectively. Additionally, there was no significant difference between the two groups for retreatment rates, procedural hemorrhagic, or thromboembolic complications.

CONCLUSION

SAC and PED are two equally efficacious modalities for endovascular treatment of ICA aneurysms arising at the communicating segment of the ICA.

Percutaneous Transverse Sinus Cannulation for Dural Arteriovenous Fistula Coiling: Operative Video

This is the case of an 84-year old woman, found to have a symptomatic transverse sinus dural arteriovenous fistula. The transverse sinus was isolated from all venous circulation and its arterial feeders stemmed from the occipital artery, precluding both arterial and venous access for effective obliteration of the fistula. Therefore the patient underwent a combined open surgical/endovascular approach, where the sinus was percutaneously cannulated through a single burr hole, allowing access for effective coiling of the fistula. In this video, we present the rationale, feasibility, and technical implications for this procedure.¹.

On Flow Diversion: The Changing Landscape of Intracerebral Aneurysm Management

Uptake of flow-diverting technology is rapidly outpacing the availability of clinical evidence. Most current usage is off-label, and the endovascular community is nearer the beginning than the end of the learning curve, given the number of devices in development. A comprehensive overview of technical specifications alongside key outcome data is essential both for clinical decision-making and to direct further investigations. Most-studied has been the Pipeline Embolization Device, which has undergone a transition to the Pipeline Flex for which outcome data are sparse or heterogeneous. Alternative endoluminal devices do not appear to be outperforming the Pipeline Embolization Device to date, though prospective studies and long-term data mostly are lacking, and between-study comparisons must be treated with caution. Nominal technical specifications may be unrelated to in situ performance, emphasizing the importance of correct radiologic sizing and device placement. Devices designed specifically for bifurcation aneurysms also lack long-term outcome data or have only recently become available for clinical use. There are no major studies directly comparing a flow-diverting device with standard coiling or microsurgical clipping. Data on flow-diverting stents are too limited in terms of long-term outcomes to reliably inform clinical decision-making. The best available evidence supports using a single endoluminal device for most indications. Recommendations on the suitability and choice of a device for bifurcation or ruptured aneurysms or for anatomically complex lesions cannot be made on the basis of current evidence. The appropriateness of flow-diverting treatment must be decided on a case-by-case basis, considering experience and the relative risks against standard approaches or observation.

Surgical and Endovascular Comprehensive Treatment Outcomes of Unruptured Intracranial Aneurysms: Reduction of Treatment Bias

BACKGROUND

Determining the risks of treatment of unruptured intracranial aneurysms is critical in the decision-making process of management. Most studies have reported the results for endovascular or surgical management. Our objective was to better delineate the risk estimates for unruptured intracranial aneurysms treated with surgical or endovascular techniques in a comprehensive fashion, according to the patients' risk profiles.

METHODS

Data were gathered from 553 patients with 658 unruptured intracranial aneurysms treated at a single institution from 2014 to 2017. The decision to treat was determined by a projected morbidity that was lower than the natural history rupture risk. Data on aneurysm size, location, patient age, and outcome at the last clinical visit (modified Rankin scale scores) were collected and analyzed retrospectively.

RESULTS

The mean patient age was 59 years, and the mean lesion size was 7.3 mm. Microsurgical clipping was used in 251 lesions (38.2%), endovascular coiling in 70 (10.6%), stent-assisted coiling in 89 (13.5%), and a pipeline embolization device in 248 (37.7%). Complications from the procedures or during hospital admission occurred 66 lesions (10% of the total). Of these 66 complications, 28 (4.32% of the total) were non-neurological, treated, and resolved without permanent morbidity. Neurologic complications occurred in 38 procedures (5.7% of the total). Of these, 7 (1%) resulted in a permanent poor outcome (modified Rankin scale score, 3-6).

CONCLUSION

Aneurysmal obliteration using endovascular and surgical approaches in a comprehensive fashion has low treatment risks for unruptured aneurysms. The nomograms generated are useful in the discussion with patients and families regarding the risks of total institutional treatment of unruptured aneurysms.

Impact craters on Pluto and Charon indicate a deficit of small Kuiper belt objects

The flyby of Pluto and Charon by the New Horizons spacecraft provided high-resolution images of cratered surfaces embedded in the Kuiper belt, an extensive region of bodies orbiting beyond Neptune. Impact craters on Pluto and Charon were formed by collisions with other Kuiper belt objects (KBOs) with diameters from ~40 kilometers to ~300 meters, smaller than most KBOs observed directly by telescopes. We find a relative paucity of small craters ≲13 kilometers in diameter, which cannot be explained solely by geological resurfacing. This implies a deficit of small KBOs (≲1 to 2 kilometers in diameter). Some surfaces on Pluto and Charon are likely ≳4 billion years old, thus their crater records provide information on the size-frequency distribution of KBOs in the early Solar System.

Evaluation of Radiological Features of the Posterior Communicating Artery and Their Impact on Efficacy of Saccular Aneurysm Treatment with the Pipeline Embolization Device: A Case Series Study

BACKGROUND

Posterior communicating artery segment aneurysms are one of the most frequent intracranial aneurysms. Currently, limited data have described the use of the pipeline embolization device (PED) in these aneurysms.

METHODS

We conducted a multicenter retrospective review of 3 prospectively collected databases of patients treated with the PED from January 2013 to December 2017. The primary objective was to assess the efficacy and safety of the PED in the treatment of saccular posterior communicating artery (PComA) aneurysms. We also assessed the effect of anatomical variations on the angiographic and clinical outcomes, including the presence of fetal PComA, vessel origin relationship to the aneurysm, and patency after PED placement.

RESULTS

We identified 57 patients with 60 saccular aneurysms; Their mean age was 60.5 years, and 49 were female (86.0%). A total of 55 aneurysms (91.7%) were unruptured. The median imaging follow-up duration was 8.5 months. Complete occlusion at the last imaging follow-up study was 84.0%. At the last follow-up examination, 94.5% of patients had a modified Rankin scale score of ≤2. The presence of fetal PComA, origin type, and patency during follow-up did have a significant effect on aneurysm occlusion (P = 0.61, P = 0.40, and P = 0.14, respectively).

CONCLUSIONS

PED use for treatment of PComA aneurysms resulted in acceptable occlusion rates. The present study did not find that fetal PComA, its origin, or its patency during follow-up had an effect on aneurysm occlusion.