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.