Cerebral artery overexpression of the NMUR1 gene is associated with moyamoya disease: a weighted gene co-expression network analysis.

INTRODUCTION: This study aimed to elucidate mechanisms underlying moyamoya disease (MMD) pathogenesis and to identify potential novel biomarkers. We utilized gene coexpression networks to identify hub genes associated with the disease. METHODS: Twenty-one middle cerebral artery (MCA) samples from MMD patients and 11 MCA control samples were obtained from the Gene Expression Omnibus (GEO) dataset, GSE189993. To discover functional pathways and potential biomarkers, weighted gene coexpression network analysis (WGCNA) was employed. The hub genes identified were re-assessed through differential gene expression analysis (DGEA) via DESeq2 for further reliability verification. An additional 4 samples from the superficial temporal arteries (STA) from MMD patients were obtained from GSE141025 and a subgroup analysis stratified by arterial type (MCA vs. STA) DGEA was performed to assess if the hub genes associated with MMD are expressed significantly greater on the affected arteries compared to healthy ones in MMD. RESULTS: WGCNA revealed a predominant module encompassing 139 hub genes, predominantly associated with the neuroactive ligand-receptor interaction (NLRI) pathway. Of those, 17 genes were validated as significantly differentially expressed. Neuromedin U receptor 1 (NMUR1) and thyrotropin-releasing hormone (TRH) were 2 out of the 17 hub genes involved in the NLRI pathway (log fold change [logFC]: 1.150, p = 0.00028; logFC: 1.146, p = 0.00115, respectively). MMD-only subgroup analysis stratified by location showed that NMUR1 is significantly overexpressed in the MCA compared to the STA (logFC: 1.962; p = 0.00053) which further suggests its possible localized involvement in the progressive stenosis seen in the cerebral arteries in MMD. CONCLUSION: This is the first study to have performed WGCNA on samples directly affected by MMD. NMUR1 expression is well known to induce localized arterial smooth muscle constriction and recently, type 2 inflammation which can predispose to arterial stenosis potentially advancing the symptoms and progression of MMD. Further validation and functional studies are necessary to understand the precise role of NMUR1 upregulation in MMD and its potential implications.

Surgery in octogenarians with intracranial meningiomas improves functional outcome at 1 year.

PURPOSE: The population is aging, and age remains an important factor in deciding surgical candidacy for intracranial tumors. The natural history and surgical behavior of meningiomas in octogenarians are not well understood. We evaluated the surgical and functional outcomes, including survival, among octogenarians with intracranial meningiomas in a single institution. METHODS: The Tumor Registry (2004-2021) was used to identify octogenarian patients (ages 80-89) diagnosed with intracranial meningioma. Primary endpoints were 1-year survival and functional outcome measured with mRS postsurgery. Kaplan-Meier, univariable Log-rank tests, and multivariable Cox hazards proportional regression models were used for assessing factors associated with overall survival (OS) in octogenarians with meningiomas who underwent surgery; logistic regression and McNemar's were used to further characterize risk factors affecting functional surgical outcome at 1 year. RESULTS: Thirty octogenarians with intracranial meningioma who underwent surgery were identified. Median age was 82.5 years and 66.6% were female patients. The 1-year median postsurgical survival probability for all octogenarians with meningioma was 86.3% and no intraoperative mortality was observed. Frailty (mFI-5, p = 0.84), tumor grade (p = 0.11), tumor size (p = 0.22), extent of resection (p = 0.35), and Karnofsky scale on admission (p = 0.93) did not significantly affect the survival in octogenarians with meningiomas which were treated surgically. The 1-year postoperative functional status of octogenarian meningioma patients who underwent surgery was significantly improved compared to pre-op mRS (McNemar's chi-squared = 9.6, df = 1, p-value = 0.001946). CONCLUSION: In octogenarians with meningiomas, surgical intervention significantly improves the pre-operative modified Rankin Scale at 1 year postsurgery in this cohort.

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.

Thrombolysis Outcomes in Patients with Diabetes and Previous Stroke: A Meta-Analysis.

BACKGROUND: Intravenous tissue-type plasminogen activator (IVtPA) is a proven treatment for acute ischemic stroke; however, diabetes mellitus (DM) and previous cerebral infarction (PCI) were considered relative contraindications for thrombolysis within the 3-4.5 h period. OBJECTIVE: The study aimed to determine the safety and efficacy of IVtPA among diabetic patients with PCI presenting with acute ischemic stroke. METHODS: Studies which evaluated the outcome of IVtPA in terms of symptomatic intracerebral hemorrhage (sICH), functional outcome in modified Rankin scale, and death among diabetic patients with PCI presenting with acute ischemic stroke within the 3-4.5 h period were systematically searched until July 2019. Screening and eligibility criteria were applied. Risk of bias was evaluated using the Newcastle-Ottawa Scale. Odds ratios (ORs) with 95% confidence interval (CI) were used to compare measures of treatment effect. Mantel-Haenszel method and random-effects model were also employed. RESULTS: Four registry-based studies with a total of 44,572 patients were included for quantitative synthesis. Giving IVtPA among DM+/PCI+ patients did not result in significantly increased rate of sICH (OR, 1.09; 95% CI, 0.88, 1.36) compared to No DM+/PCI+ patients. However, there was significantly higher mortality (OR, 1.81; 95% CI, 1.60, 2.06) in the DM+/PCI+ group. Conversely, among those who survived, the DM+/PCI+ patients were more functionally independent at 3 months (OR, 0.76; 95% CI, 0.61, 0.94). CONCLUSION: Limited evidence suggests that thrombolysis in DM+/PCI+ patients does not result in significantly higher incidence of sICH and may improve functional independence. However, the significantly higher mortality in this group warrants an assessment of the individualized risk-benefit ratio in the use of IVtPA.

Qualitative Posttreatment Diffusion-Weighted Imaging as a Predictor of 90-day Outcome in Stroke Intervention.

PURPOSE: The aim was to assess the ability of post-treatment diffusion-weighted imaging (DWI) to predict 90-day functional outcome in patients with endovascular therapy (EVT) for large vessel occlusion in acute ischemic stroke (AIS). METHODS: We examined a retrospective cohort from March 2016 to January 2018, of consecutive patients with AIS who received EVT. Planimetric DWI was obtained and infarct volume calculated. Four blinded readers were asked to predict modified Rankin Score (mRS) at 90 days post-thrombectomy. RESULTS: Fifty-one patients received endovascular treatment (mean age 65.1 years, median National Institutes of Health Stroke Scale (NIHSS) 18). Mean infarct volume was 43.7 mL. The baseline NIHSS, 24-hour NIHSS, and the DWI volume were lower for the mRS 0-2 group. Also, the thrombolysis in cerebral infarction (TICI) 2b/3 rate was higher in the mRS 0-2 group. No differences were found in terms of the occlusion level, reperfusion technique, or recombinant tissue plasminogen activator use. There was a significant association noted between average infarct volume and mRS at 90 days. On multivariable analysis, higher infarct volume was significantly associated with 90-day mRS 3-5 when adjusted to TICI scores and occlusion location (OR 1.01; CI 95% 1.001-1.03; p = 0.008). Area under curve analysis showed poor performance of DWI volume reader ability to qualitatively predict 90-day mRS. CONCLUSION: The subjective impression of DWI as a predictor of clinical outcome is poorly correlated when controlling for premorbid status and other confounders. Qualitative DWI by experienced readers both overestimated the severity of stroke for patients who achieved good recovery and underestimated the mRS for poor outcome patients. Infarct core quantitation was reliable.

Accuracy and Safety of External Ventricular Drain Placement by Physician Assistants and Nurse Practitioners in Aneurysmal Acute Subarachnoid Hemorrhage.

BACKGROUND: In the current dynamic health environment, increasing number of procedures are being completed by advanced practitioners (nurse practitioners and physician assistants). This is the first study to assess the clinical outcomes and safety of external ventricular drain (EVD) placements by specially trained advanced practitioners. OBJECTIVE: Compare the safety and outcomes of EVD placement by advanced practitioners in patients with subarachnoid hemorrhage (SAH). METHODS: A cohort comparison study was performed from an aneurysmal SAH database selecting patients treated with EVD from a single major academic institution in the USA between June 2007 and June 2017. Safety, accuracy, and complications of EVD placement were compared between advanced practitioners and neurosurgical physicians (attending neurosurgeon and subspecialty clinical fellow). Statistical analysis was performed using the Mann-Whitney test for continuous variables and χ2 test for categorical variables, with p values set at < 0.05 for significance. RESULTS: We identified 203 patients for this cohort with 238 EVD placements; eighty-seven (36.6%) placements were performed by advanced practitioners and 151 (63.4%) by neurosurgeons. Most of the ventriculostomies were placed in the emergency room (n = 114; 47.9%). Additional procedures performed concurrently with the EVD placements were significantly higher among the physicians' group (21.8 vs. 4.6%; p < 0.001). Bedside placement and usage of Ghajar guide were significantly higher among advanced practitioner's (58.3 vs. 98.9 and 9.9 vs. 64.4%, respectively, with a p < 0.001 for both). There were, however, no significant differences in terms of the number of attempts for insertion, intraprocedural complications, tract hemorrhages, accuracy, infection rates, catheter dislodgments, and need for repositioning/replacement of EVD. CONCLUSION: After appropriate training, EVD placement can be safely performed by advanced practitioners with an adequate accuracy of placement.

Embolization Prior to Radiosurgery in Treatment of Arteriovenous Malformations: Defining Radiosurgery Target Dose with Nidal Volume Reduction.

INTRODUCTION: Arteriovenous malformations (AVMs) can be treated with observation, surgery, embolization, stereotactic radiosurgery (SRS), or a combination of therapies. SRS has been used for AVMs that pose a high risk of surgery, such as in deep or eloquent anatomic locations. Smaller AVMs, <3 cm, have been shown to have higher rates of complete obliteration after SRS. For AVMs that are a larger size, embolization prior to SRS has been used to reduce the size of the AVM nidus. In this study we analyzed embolization prior to SRS to reduce nidal volume and describe imaging techniques to target for SRS post embolization. METHODS: We retrospectively reviewed all patients at a single academic institution treated with embolization prior to SRS for treatment of AVMs. We then used contrast enhanced magnetic resonance imaging (MRI) to contour AVM volumes based on pre-embolization imaging and compared to post-embolization imaging. Planned AVM volume prior to embolization was then compared to actual treated AVM volume. RESULTS: We identified 11 patients treated with embolization prior to SRS from 2011-2023. Median AVM nidal volume prior to embolization was 7.69 mL and post embolization was 3.61 ML (P < 0.01). There was a 45.5% obliteration rate at follow up in our series, with 2 minor complications related to radiosurgery. CONCLUSIONS: In our cohort, embolization prior to SRS resulted in a statistically significant reduction in AVM nidal volume. Therefore, embolization prior to SRS can result in dose reduction at time of SRS treatment allowing for decreased risk of SRS complications without higher embolization complication rates.

Management of Intracranial Aneurysms that Do Not Occlude on Initial Follow-up After Treatment With the Pipeline Embolization Device.

BACKGROUND AND OBJECTIVES: The pipeline embolization device (PED) has become widely accepted as a safe and efficacious treatment for intracranial aneurysms with high rates of complete occlusion at initial follow-up. For aneurysms that are not completely occluded at initial follow-up, further treatment decision-making is varied. Furthermore, the risk of aneurysmal rupture in these incompletely occluded aneurysms after PED is not known. The objective of this study was to determine treatment decision-making that results in increased occlusion status at final follow-up and to evaluate risk of rupture in those aneurysms that do not go onto occlusion. METHODS: This study is a retrospective review of prospective data for intracranial aneurysms treated with PED at two institutions from 2013 to 2019. Aneurysms with near-complete or incomplete occlusion at initial follow-up were included in the statistical analysis. RESULTS: There were 606 total aneurysms treated at two academic institutions with PED with incomplete occlusion at initial follow-up in 134 aneurysms (22.1%). Of the 134 aneurysms that were nonoccluded at initial follow-up, 76 aneurysms (56.7%) went on to complete or near complete occlusion with final complete or near complete occlusion in 90.4% of all aneurysms treated. The time to final imaging follow-up was 28.2 months (13.8-44.3) Retreatment with a second flow diverter was used in 28 aneurysms (20.9%). No aneurysms that were incompletely occluded at initial follow-up had delayed rupture. Furthermore, older patient age was statistically significant for incomplete occlusion at initial follow-up ( P = .05). CONCLUSION: Intracranial aneurysms treated with the PED that do not occlude at initial follow-up may go on to complete occlusion with continuous observation, alteration in antiplatelet regimens, or repeat treatment. Delayed aneurysmal rupture was not seen in patients with incomplete occlusion.

Thromboembolic Events After the Coverage of Anterior Cerebral Artery with Flow Diversion: A Single Institution Series and Systematic Review.

BACKGROUND: Advances in the use of flow diversion (FD) now extend to bifurcation aneurysms; herein, we compare thromboembolic events in patients with internal carotid artery (ICA) aneurysms treated with and without exclusion of the anterior cerebral artery (ACA). METHODS: Retrospective analysis of aneurysms in the terminal ICA treated with FD from 2013 to 2023 at a single-center study. Procedures were classified according to the coverage at the origin of the ACA and compared through bivariate-analysis. A review was also carried on PubMed, Web of Science, and EMBASE until April 2024, adhering to the PRISMA reporting guidelines. RESULTS: Ninety-five patients harboring 113 aneurysms treated in 102 procedures were evaluated. Fifty-eight were treated covering the ACA origin. Dual antiplatelet regimens included aspirin-clopidogrel (50%), aspirin-ticagrelor (44.1%), and aspirin-prasugrel (4.9%). Thromboembolic events occurred in 6 patients (5.9%), all of which presented with large vessel occlusion of the ICA, but without reaching statistical difference in the 2 treated cohorts (P = 0.46). At a median clinical follow-up of 5.95 months, there were no differences in the functional outcomes in the 2 groups (P = 0.22). Contralateral angiographic runs post-treatment after covering the ACA origin demonstrated increase in the A1 (median: 0.45 mm; IQR = 0.4-1.2) and ICA diameter (median: 0.55 mm; IQR = 0.1-1.2). After pooling data from literature and our cohort, complete side branch occlusion after the coverage of ACA was seen in 25% of branches (95%CI = 0.16-0.36), and thromboembolic events were observed after 3% (95%CI = 0.01-0.04) of procedures. CONCLUSIONS: Thromboembolic events can occur in distal ICA aneurysms treated with FD, but no significant association was seen with covering the ACA origin.

The evolution and future directions of bypass surgery.

Cerebral bypass surgery is one of the most complex and elegant procedures in neurosurgery. It involves several meticulous steps that test the skills of even the most prepared neurosurgeons. This surgery has transcended its traditional role in arterial stenosis and atherosclerosis, expanding its applications to include flow preservation techniques for complex conditions such as aneurysms, tumors, and vascular malformations. The decreased number of procedures performed across many hospitals reflects the development of newer endovascular therapies but is also due to the results of the extracranial-intracranial bypass study, the Carotid Occlusion Surgery Study, and the Carotid and Middle Cerebral Artery Occlusion Surgery Study, which have raised questions about the efficacy of cerebral bypass surgery for individuals with carotid artery occlusion who are prone to ischemic stroke. Despite this, there is still a potential benefit of bypass surgery for patients with hemodynamic impairment refractory to medical management. Also, revascularization in moyamoya vasculopathy is an effective strategy for preventing ischemic and hemorrhagic events in both children and adults. Additionally, innovations in the technique, such as the flow-regulated bypass and intraoperative flow assessment, aim to minimize perioperative morbidity. Despite bypass surgery being less performed in this current era, the teaching and development of these skills are still encouraged for future neurosurgeons, as a role for bypass will exist for the foreseeable future.

Defining light transmission aggregometry cutoff values for clopidogrel and aspirin resistance in flow diversion treatment of intracranial aneurysms.

OBJECTIVE: Concern about thromboembolic events after flow diversion (FD) warrants dual antiplatelet therapy for 3 to 6 months. Platelet function tests are routinely performed prior to the procedure to detect clopidogrel responsiveness, as resistance is associated with CYP2C19 gene polymorphisms. This study aimed to identify optimal cutoff values in light transmission aggregometry (LTA) for clopidogrel and aspirin as predictive indicators of thromboembolic complications. METHODS: The authors conducted a retrospective analysis of aneurysms treated with FD between 2013 and 2023 at a single academic institution. Patients with LTA data for adenosine diphosphate (ADP) and arachidonic acid (ARA) were included, excluding those with aborted procedures. Receiver operating characteristic curves were plotted for ADP and ARA assays to determine optimal cutoff values. RESULTS: A total of 442 patients harboring 552 aneurysms treated in 485 procedures were selected for this analysis. Complete and near-complete aneurysm occlusion on the last radiological follow-up was achieved in 81.8% of aneurysms in a median last imaging follow-up of 13.9 months. A good functional outcome (modified Rankin Scale score ≤ 2) was achieved in 96.3% of patients on the last follow-up. Thromboembolic complications occurred in 4.9% of procedures, and intracranial hemorrhagic complications in 1.9%. For the ADP assay, a value ≥ 40% reached a sensitivity of 82.1% and a specificity of 42.9% with a positive likelihood ratio (LR) of 1.50. For the ARA assay, a value ≥ 13.5% reached a sensitivity of 82.1% and a specificity of 45.6% with a positive LR of 1.51. CONCLUSIONS: This study analyzed the largest FD-treated cohort in which optimal LTA platelet function thresholds for clopidogrel were evaluated and is the first to assess LTA values for aspirin. The authors found that values ≥ 40% for clopidogrel and ≥ 13.5% for aspirin were optimal for predicting thromboembolic complications after FD in treating aneurysms.

Endovascular Treatment of Basilar Apex Aneurysms: An Updated Systematic Review and Meta-Analysis in the Era of Flow Diversion.

BACKGROUND: Endovascular options for the treatment of basilar apex aneurysms (BAAs) are heterogeneous, and evidence is limited to retrospective cohorts and case series. We seek to evaluate the efficacy and complications associated with various endovascular treatment methods of BAAs. METHODS: Systematic review of PubMed, Embase, and Web of Science adhering to the PRISMA guidelines. Retrospective and prospective studies evaluating endovascular treatment of BAAs between January 2010 and July 2024 were included. Relevant information including occlusion rates, aneurysm recurrence, retreatment rates, and complications were subjected to meta-analysis. RESULTS: Fifteen studies with 1,049 BAAs were included. The median aneurysm diameter was 8.5 mm (range 4.6-19.75), with a median follow-up of 33.7 months (range 6.0-117.6). Residual aneurysm filling occurred in 24% after primary coiling (95% CI=0.16-0.32), 25% after single stent-assisted coiling (s-SAC; 95% CI=0.04-0.46), 25% after Y-stenting (95% CI=0.12-0.37), and 23% after flow diverter stenting (FDS; 95% CI=0.11-0.35). Recurrence rates were high for primary coiling (27%, 95% CI=0.18-0.36) and s-SAC (19%, 95% CI=0.13-0.26), but significantly lower for Y-stenting (9%, 95% CI=0.03-0.15) and FDS (4%, 95% CI=-0.04-0.11). Retreatment rates were 19% for primary coiling (95% CI=0.12-0.26), 17% for s-SAC (95% CI=0.07-0.27), 5% for Y-stenting (95% CI=-0.03-0.12), and 13% for FDS (95% CI=-0.01-0.27). Meta-regression indicated larger aneurysms had higher complication rates (p=0.02). Thromboembolic events were most frequent with FDS and Y-stenting (12%). CONCLUSION: Occlusion rates were similar across treatments, but recurrence rates were significantly lower after Y-stenting and FDS treatments compared to primary coiling, although they carried a higher number of thromboembolic complications.

The Neurovascular Disease Management Course: a Medical Student Opportunity for Early Exposure and Technical Development in Vascular Neurosurgery.

BACKGROUND: As endovascular neurosurgery techniques continue to evolve, medical students in the United States have widely varying exposures to the field, particularly with respect to opportunities for hands-on experiences. Current medical school curricula could benefit from a novel and adaptive course on vascular neurosurgery to increase student exposure earlier in their training. METHODS: We launched a yearly hands-on vascular neurosurgery course for medical students and residents. The day-long course is a combination of lectures focused on neurovascular disease and management accompanied by hands-on sessions where students practiced fundamental microsurgery and angiography techniques using real microscopes and angiography simulators. We surveyed the students before and after each of the two courses. The survey following the second annual course included quiz questions the students had not previously seen. RESULTS: Over two courses, we had 149 attendees, 71.8% of which were first and second-year medical students representing fifteen institutions. The average survey completion rate was 41.4% for the four surveys across the two courses. Attendees' interest in pursuing a surgical specialty (t= 1.815, p=0.039) along with their comfort with neuroanatomy (t= 8.780, p=< 0.001) and neurosurgical disease (t= 6.133, p=< 0.001) was significantly elevated after the completion of the second course. Responses to the post-survey showed a good grasp of the fundamentals with 68% of attendees answering 70% of the quiz questions correctly. CONCLUSION: An interactive course on vascular neurosurgery may be an effective vehicle to provide medical students with exposure to the field and the opportunity to learn the fundamentals.

Comparison of Thromboembolic Events Between Pipeline Embolization Device (PED) Shield and PED/PED Flex: A Propensity Score-Matched Analysis.

BACKGROUND AND OBJECTIVES: The pipeline embolization device (PED) Flex with Shield technology is a third-generation flow diverter used for intracranial aneurysm treatment designed to decrease thrombogenicity through a phosphorylcholine coating. Herein, we aim to compare the rate of thromboembolic events in PED with Shield technology and PED without it through propensity score matching. METHODS: We conducted a retrospective analysis of aneurysms treated with PED first-generation/PED Flex and PED with Shield between 2013 and 2023 at a single academic institution. Patients were matched through propensity score by controlling for confounding factors including age, smoking history, diabetes, previous subarachnoid hemorrhage, modified Rankin Scale pretreatment, location, aneurysm size, previous treatment, and clopidogrel or aspirin resistance. After matching, we evaluated for periprocedural and postoperative thromboembolic events. Data analysis was performed using Stata 14. RESULTS: A total of 543 patients with 707 aneurysms treated in 605 procedures were included in the analysis. From these, 156 aneurysms were treated with PED with Shield (22.07%) and 551 (77.93%) without Shield technology. Propensity score matching resulted in 84 matched pairs. The rate of thromboembolic events was 3.57% for PED Shield and 10.71% for PED first-generation/PED Flex ( P = .07), while retreatment rates were 2.38% for PED Shield and 8.32% for PED Flex ( P = .09). Complete occlusion at first ( P = .41) and last imaging follow-up ( P = .71), in-stent stenosis ( P = .95), hemorrhagic complications ( P = .31), and functional outcomes ( P = .66) were comparable for both groups. CONCLUSION: This is the first study in the literature performing a propensity scored-matched analysis comparing PED with PED with Shield technology. Our study suggests a trend toward lower thromboembolic events for PED Shield, even after controlling for aspirin and clopidogrel resistance, and a trend toward lower aneurysm retreatment rates with PED Shield, without reaching statistical significance.

Thromboembolic Events in the Posterior Circulation After Flow Diversion-A Closer Look at Coverage of the Posterior Cerebral Artery.

BACKGROUND: Flow diversion for bifurcation aneurysms requires excluding one of the branches from the parent artery, raising concern for ischemic events. We evaluated thromboembolic events and their relationship with covering the origin of the posterior cerebral artery (PCA). METHODS: This retrospective analysis included patients with confirmed basilar and proximal PCA aneurysms treated with flow diversion between 2013 and 2023. Procedures were classified according to the coverage of the origin of the PCA. Thromboembolic events associated with the excluded PCA were evaluated. RESULTS: Of the total 28 aneurysms included, 7 were at the basilar tip, 16 in the basilar trunk, and 5 in the first segment of the PCA; 15 were treated by excluding one of the PCAs. Dual antiplatelet therapy included aspirin and ticagrelor (57.1%), aspirin and clopidogrel (35.7%), or aspirin and prasugrel (3.57%). Complete and near-complete aneurysm occlusion was achieved in 80.8% of the aneurysms treated at a median follow-up of 12.31 months. Thromboembolic complications occurred in 3 patients (2 with basilar perforator stroke and 1 with basilar in-stent thrombosis). However, the difference in these events was not statistically significant between patients with PCA coverage and those without (P = 0.46). Diminished flow and a lack of flow was seen in 8 and 7 of the covered vessels, respectively. A modified Rankin scale score of ≤2 was reported for 89.3% of patients at a median clinical follow-up of 5.5 months. CONCLUSIONS: The incidence of thromboembolic events is high in distal basilar and proximal PCA aneurysms; however, PCA coverage was not associated with their occurrence. There was no difference in postprocedural disability between patients whose aneurysms were treated by excluding one of the PCAs and those who were not.

Comparison of Postoperative Seizures Between Burr-Hole Evacuation and Craniotomy in Patients With Nonacute Subdural Hematomas: A Bi-Institutional Propensity Score-Matched Analysis.

BACKGROUND AND OBJECTIVES: Postoperative seizures are a common complication after surgical drainage of nonacute chronic subdural hematomas (SDHs). The literature increasingly supports the use of prophylactic antiepileptic drugs for craniotomy, a procedure that is often associated with larger collections and worse clinical status at admission. This study aimed to compare the incidence of postoperative seizures in patients treated with burr-hole drainage and those treated with craniotomy through propensity score matching (PSM). METHODS: A retrospective cohort analysis was conducted on patients with surgical drainage of nonacute SDHs (burr-holes and craniotomies) between January 2017 to December 2021 at 2 academic institutions in the United States. PSM was performed by controlling for age, subdural thickness, subacute component, and preoperative Glasgow Coma Scale. Seizure rates and accompanying abnormalities on electroencephalographic tracing were evaluated postmatching. RESULTS: A total of 467 patients with 510 nonacute SDHs underwent 474 procedures, with 242 burr-hole evacuations (51.0%) and 232 craniotomies (49.0%). PSM resulted in 62 matched pairs. After matching, univariate analysis revealed that burr-hole evacuations exhibited lower rates of seizures (1.6% vs 11.3%; P = .03) and abnormal electroencephalographic findings (0.0% vs 4.8%; P = .03) compared with craniotomies. No significant differences were observed in postoperative Glasgow Coma Scale (P = .77) and length of hospital stay (P = .61). CONCLUSION: Burr-hole evacuation demonstrated significantly lower seizure rates than craniotomy using a propensity score-matched analysis controlling for significant variables.

A Novel Scoring System Predicting Aneurysm Incomplete Occlusion after Flow Diversion: A 10-year experience.

BACKGROUND: Factors impacting the rate of aneurysm occlusion after FD have been well described in the literature. In this paper, we sought to evaluate those variables to develop and validate a scoring system predicting aneurysm incomplete occlusion after FD. METHODS: Retrospective review of patients with intracranial aneurysms treated with FD at a single institution between March 2013 and March 2023. Multivariable logistic regression model was developed using factors associated with aneurysm incomplete occlusion. The ABC scoring system consisted of: Age (< 60 years old: 0, 60-69 years: 1, 70-79: 2, and ≥80: 3), Branch coming out of the aneurysm dome/neck (yes: 2, no:0), and Cigarette smoking history (never-smoker:1, current or past smoker: 0). The scoring system performance was evaluated with receiver operating characteristic curve and calculating the area under the curve (AUC). RESULTS: A total of 449 patients with 563 aneurysms treated in 482 procedures were evaluated. Most cases were females (81.7%) with a median age of 59 years-old. At a median follow-up of 13.2 months, 84.0% of aneurysms were completely or near-complete occluded. The scoring system had an AUC of 0.71. A value ≥2, reached a sensitivity of 74.4%, specificity of 60.9%, an LR+ of 1.90, and proved to be reliable in predicting the risk of incomplete occlusion (OR=4.53; 95% confidence interval, 2.73-7.54; P < 0.001). CONCLUSION: The proposed ABC scoring system can be used to evaluate the risk of aneurysm incomplete occlusion after treatment with FD, identifying patients who would benefit from adjunctive coiling or alternate treatment modalities.

Acute Coiling With Delayed Flow Diversion for Posterior Communicating Segment Internal Carotid Artery Aneurysms: A Multicenter Case Series.

BACKGROUND AND OBJECTIVES: In ruptured posterior communicating artery (PcomA) aneurysms, the protection of the aneurysm dome alone with initial subtotal coiling decreases the risk of rerupture in the acute setting but does not provide durable/definitive long-term protection against delayed rupture. Delayed flow diverter (FD) placement can be a potential alternative to definitively secure these aneurysms without increasing the risk of complications and PComA occlusion. We analyzed PComA aneurysms treated with a planned delayed FD after primary coiling and assess radiographic and clinical outcomes. METHODS: We performed a retrospective study of prospectively collected data for intracranial aneurysms treated with planned FD at 2 institutions from 2013 to 2022. PComA aneurysms that underwent primary coiling and delayed FD placement were included for analysis. RESULTS: There were 29 PComA aneurysms identified that were included in the analysis. Patients were mostly female (79.3%), with a median age of 60 years. The mean aneurysm maximum diameter was 7.2 mm ± (5.3). Immediate Raymond-Roy occlusion grade after primary coiling was I in 48.3%, II in 41.4%, and III in 10.3% of aneurysms. The median time from initial coiling to planned delayed FD placement was 6.3 months (3.2-18.6). A total of 21 (72.4%) aneurysms underwent follow-up radiological imaging. Complete and near-complete occlusion status was achieved in 76.2% of the evaluated aneurysms. There were no retreatments and no evidence of delayed aneurysm rupture. One case (3.5%) presented thromboembolic complications and 1 (3.5%) intracranial hemorrhagic complication after FD placement, which was associated with mortality. Most patients (90.5%) had a modified Rankin scale of ≤2 on the last follow-up. CONCLUSION: Primary coiling with planned staged FD placement is effective for treating ruptured PComA aneurysms with high occlusion rates and low complications.

Flow diversion: a disruptive technology coming of age. Lessons learned and challenges for the future.

Intracranial aneurysm treatment has been revolutionized over the last decade with the development of flow diversion technology. The use of this technology has evolved rapidly and has proven that cerebrovascular disease treatment remains one of the forefront innovation areas in neurosurgery. The good results on the treatment of internal carotid artery aneurysms up to the communicating segment have motivated the use of flow diversion beyond the circle of Willis and in the posterior circulation. Further advances and innovations of flow-diverting devices are underway and intended to improve the safety and efficacy of this therapy. This review article provides a detailed discussion about the origin, mechanism of action, initial experience, complications, types of devices, and future perspectives of flow diversion technology.

Flow Diversion for the Treatment of Posterior Inferior Cerebellar Aneurysms: A Novel Classification of Posterior Inferior Cerebellar Artery Origin.

BACKGROUND AND OBJECTIVES: Flow diversion (FD) for posterior circulation aneurysms, such as proximal posterior inferior cerebellar artery (PICA) aneurysms, remains "off-label" and controversial. Although there are reports of using FD in the vertebral artery (VA) to treat PICA aneurysms, the differences between structural PICA-origin variants have not been explored. We analyzed PICA aneurysms treated with FD, assessed radiographic and clinical outcomes, and presented a novel classification of the PICA origin in relationship to aneurysm anatomy. METHODS: We performed a retrospective study of prospective data for intracranial aneurysms treated with FD at a major academic institution from 2013 to 2022. Proximal PICA aneurysms that underwent FD placement in the V4 segment of the vertebral artery were included for analysis. A literature review was performed on PubMed to evaluate previously published cases. The PICA origin was characterized by 4 distinct subtypes. Type 1 describes the PICA originating adjacent/separate to the aneurysm neck, Type 2 with the PICA originating from the aneurysm neck, Type 3 with the PICA originating from the aneurysm dome, and Type 4 (True PICA aneurysm) with the aneurysm located proximally on PICA, distal to the PICA-VA junction. RESULTS: Thirteen proximal PICA aneurysms were identified and included in the analysis. Patients were primarily female (76.9%), with a median age of 62 years. The aneurysm median maximum diameter was 5.8 mm. From the total sample (institutional and literature review cases), type 1 had a 100% complete and near-complete occlusion rate, type 2 had 75.0%, type 3 had 88.9%, and type 4 had 75%. The overall complete and near-complete occlusion rate was 83.3% (20/24). CONCLUSION: FD in the V4 VA segment is an effective way to treat proximal PICA aneurysms. Exploring the relationship between PICA origin is a helpful method in predicting occlusion rates for proximal PICA aneurysms and may lead to improved treatment considerations.