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Background: Multiple factors have been proposed to affect the vessel ingrowth from the superficial temporal artery (STA) after Encephalo-Duro-Arterio-Synangiosis (EDAS)., Methods: This retrospective single-center analyses included patients with Moyamoya Disease (MMD) undergoing EDAS from January 1st, 2013, to December 31st, 2023. Evaluated variables included demographic characteristics, clinical presentation, technical details, modified Rankin Scale (mRS) scores, and radiographic outcomes. Univariate and multivariate analysis was performed to identify factors favoring the ingrowth of collaterals from the STA., Results: Forty adult patients with MMD, most commonly females (77.5 %) with a median age of 48, underwent 56 EDAS. The most common initial presentations were ischemic events (75.0 %), followed by hemorrhagic events (27.5 %) and seizures (7.5 %). Digital angiography performed at a median of 13.7 months post-procedure revealed collateral growth from the STA in 78.6 % of cases, with a Matsushima grade A identified in 35.7 % of the revascularized hemispheres. Univariate analysis showed more collaterals in patients with a larger preoperative STA diameter (p=0.035), higher Suzuki grades (p=0.021) and longer angiographic follow-ups (p=0.048). Patients with occlusion of the internal carotid artery (ICA; p<0.01), middle cerebral artery (MCA; p<0.01), or anterior cerebral artery (ACA; p<0.01) also had more collateral ingrowth. Multivariate analysis revealed that ICA occlusion (OR=6.54; 95 % CI=1.03-41.48) and ACA occlusion (OR=6.52; 95 % CI=1.02-41.67) as predictors of collateral ingrowth from the STA., Conclusion: ICA and ACA occlusion were associated with success after EDAS. Longer follow-ups and larger STA demonstrated significant association on univariate analysis, but lost significance after adjusting for other procedural characteristics., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Introduction: Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy effectively treats medication-resistant essential tremor (ET). Usually, intracranial calcifications are excluded as no-pass zones because of their low penetrability which may limit the effectiveness of treatment and lead to unintended side effects. This case report illustrates the efficacy of unilateral MRgFUS for tremor control in a patient with extensive basal ganglia calcifications due to Fahr's disease., Case Presentation: A 69-year-old right-handed male with debilitating Fahn-Tolosa-Marin grade 3-4 bilateral hand tremor underwent unilateral left MRgFUS thalamotomy. The treatment involved careful preoperative planning to accommodate his extensive basal ganglia calcifications, element path consideration, and skull density ratio to ensure accurate and effective lesioning. Posttreatment, the patient exhibited complete abolition of tremor on the treated side with minor transient dysarthria and imbalance. Follow-up at 12 weeks posttreatment showed sustained tremor relief and an absence of any adverse effects, validating the procedural adjustments made to accommodate the unique challenges posed by his intracranial calcifications., Conclusion: MRgFUS can be safely and effectively applied in certain patients with extensive basal ganglia calcifications - in this case, due to Fahr's disease. This case report suggests expanding the application of MRgFUS to patients with extensive intracranial calcifications who previously might not have been considered suitable candidates for MRgFUS., (© 2024 S. Karger AG, Basel.)

Objective: As endovascular interventions become safer and their use more prevalent for treating extracranial pseudoaneurysms, fewer pseudoaneurysms are treated with medical therapy alone. This study aimed to assess the indications for intervention and the safety of medical management., Methods: A dual-center retrospective analysis was conducted on patients diagnosed with extracranial carotid and vertebral pseudoaneurysms between December 2006 and June 2023., Results: Of 145 pseudoaneurysms, 121 (83%) received medical therapy, 22 (15%) were treated endovascularly, and 2 (1.4%) were treated with open surgery. In the medical group, there were 2 (1.9%) complications, one unrelated to the pseudoaneurysm. In the intervention group, there were 3 (16%) complications, with 1 patient requiring two retreatments and sacrifice of the vessel. Major trauma (OR 4.0, 95% CI 1.3-14; p = 0.02), use of digital subtraction angiography as the initial imaging modality (OR 9.8, 95% CI 2.5-42; p < 0.01), and a maximum lesion diameter > 6 mm (OR 5.3, 95% CI 1.4-25; p = 0.03) proved to be significant in the decision to intervene. At a median follow-up of 18.1 months, 94.7% of the lesions treated with intervention healed completely compared with 19% of aneurysms in the medical group. Among those medically managed that did not resolve, the median change in diameter was -0.4 mm (IQR -1.8 to 0.4 mm). Age ≤ 50 years and aneurysm maximum diameter ≤ 6 mm predicted healing at follow-up in the medical group with 92% specificity and 65% sensitivity (area under the curve 0.87). At follow-up, 98% of patients were functionally independent (modified Rankin Scale score ≤ 2)., Conclusions: Medical management alone is safe for most extracranial pseudoaneurysms, resulting in significantly fewer complications than endovascular intervention. Maximum diameter ≤ 6 mm and age ≤ 50 years were significant predictors of pseudoaneurysm resolution with medical therapy alone. Lesions that do not heal do not cause further symptoms or require additional intervention.

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 2 courses. The survey following the second annual course included quiz questions the students had not previously seen., Results: Over 2 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 4 surveys across the 2 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., Conclusions: 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., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Factors impacting the rate of aneurysm occlusion after flow diversion (FD) have been well described in the literature. In this article, 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., 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 area under the curve of 0.71. A value ≥ 2, reached a sensitivity of 74.4%, a specificity of 60.9%, a likelihood ratio+ of 1.90, and proved to be reliable in predicting the risk of incomplete occlusion (odds ratio = 4.53; 95% confidence interval: 2.73-7.54; P < 0.001)., Conclusions: 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 alternative treatment modalities., (Copyright © 2024 Elsevier Inc. All rights reserved.)

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 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (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 1049 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-stents (95% CI = 0.12-0.37), and 23% after flow diverter stent (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-stents (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-stents (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-stents(12%)., Conclusions: Occlusion rates were similar across treatments, but recurrence rates were significantly lower after Y-stents and FDS compared to primary coiling, although they carried a higher number of thromboembolic complications., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The Matsushima grade has traditionally been used to evaluate vessel ingrowth from the superficial temporal artery after encephalo-duro-arterio-synangiosis (EDAS) for Moyamoya disease (MMD) patients. However, this grading is subjective and prone to measurement variability. Herein, we propose the orbital grading system quantifying leptomeningeal and burr hole-related vessel-ingrowth from the superficial temporal artery and/or middle meningeal artery to the middle and anterior cerebral arteries post EDAS in MMD patients., Methods: An anatomical classification was developed by reference to 2 parallel vertical lines from the bony landmarks of the orbit, categorized from Grade 0-3. Regression models were used to compare clinical and functional outcomes of our grading system with the Matsushima scale., Results: Forty MMD patients, with median age of 48 years, mostly females (72.5%), underwent 56 EDAS procedures. Presentation included ischemic events (65.0%), hemorrhage (22.5%), and seizures (7.5%). Most patients were categorized as Suzuki ≥ IV (69.5%). Fifty EDAS (89.9%) had concurrent burr holes placed (parietal and frontal regions). At a median follow-up of 13.7 months, collateral growth was graded as follows: grade 0 (6; 10.8%), grade 1 (12; 21.4%), grade 2 (23; 41.1%), and grade 3 (15; 26.8%). Linear regression showed similarities in the distribution between the orbital grading system and Matsushima grading (r = 0.86; P < 0.01). Ischemic events were fewer in hemispheres categorized as grade 2-3 compared to grade 0-1 (P = 0.047) as well as in Matsushima grading A or B compared to C (P = 0.047)., Conclusions: The orbital grading system demonstrated agreement in identifying postoperative ischemic events as the Matsushima grade and provides a more practical and objective evaluation of collateral vessel ingrowth after EDAS with and without burr holes., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: This study aims to evaluate the length of stay (LOS) in patients who had adjunct middle meningeal artery embolization (MMAE) for chronic subdural hematoma after conventional surgery and determine the factors influencing the LOS in this population., Methods: A retrospective review of 107 cases with MMAE after conventional surgery between September 2018 and January 2024 was performed. Factors associated with prolonged LOS were identified through univariable and multivariable analyses., Results: The median LOS for MMAE after conventional surgery was 9 days (interquartile range = 6-17), with a 3-day interval between procedures (interquartile range = 2-5). Among 107 patients, 58 stayed ≤ 9 days, while 49 stayed longer. Univariable analysis showed the interval between procedures, type of surgery, MMAE sedation, and the number of complications associated with prolonged LOS. Multivariable analysis confirmed longer intervals between procedures (odds ratio [OR] = 1.52; P < 0.01), ≥2 medical complications (OR = 13.34; P = 0.01), and neurological complications (OR = 5.28; P = 0.05) were independent factors for lengthier hospitalizations. There was a trending association between general anesthesia during MMAE and prolonged LOS (P = 0.07). Subgroup analysis revealed diabetes (OR = 5.25; P = 0.01) and ≥2 medical complications (OR = 5.21; P = 0.03) correlated with a LOS over 20 days, the 75th percentile in our cohort., Conclusions: The interval between procedures and the number of medical and neurological complications were strongly associated with prolonged LOS in patients who had adjunct MMAE after open surgery. Reducing the interval between the procedures and potentially performing both under 1 anesthetic may decrease the burden on patients and shorten their hospitalizations., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Primary pituitary lymphoma (PPL) is a rare finding in immunocompetent patients, with only 54 patients reported to date (including ours). It presents most often with headache and hypopituitarism, with MRI findings comparable to more common pituitary tumours, making the diagnosis challenging. There is no consensus on the ideal management for these lesions with the role of surgical resection not clearly established., Case Report: We present here a 49-year-old female who presented with acute vision loss and was found to have PPL of diffuse large B-cell lymphoma, non-germinal centre type. The radiologic findings were distinct from prior cases with haemorrhagic components and perilesional edoema in the bilobed sellar mass. Surgical resection was halted when a diagnosis of lymphoma was suspected. This decision was based on the guidelines for the treatment of primary CNS lymphoma (PCNSL) and the lack of evidence to support surgical resection of PPL specifically. Our patient lacked mutations commonly associated with a poor prognosis in DLBCL, such as TP53 and BCL6. She remains in remission with normal vision nearly two years after treatment with minimal resection, MR-CHOP, and consolidation radiotherapy., Conclusion: We highlight here the clinical and diagnostic features of PPL to guide clinicians to early recognition and diagnosis. Surgical resection should be limited to what is necessary to obtain a diagnosis and critical decompression; otherwise, these lesions respond excellently to steroids and typical chemoradiation regimens.

Objective: Thromboembolic (TE) events are among the most feared complications after flow diversion (FD) and have been reported to occur even with adequate dual antiplatelet therapy. Herein, the authors characterize thrombotic and embolic events that developed after FD, focusing on the morbidity of each of these events and the predisposing factors associated with their development., Methods: A retrospective analysis of aneurysms treated with FD at a single institution in the US between 2013 and 2023 was performed. The authors documented the emergence of intraprocedural and postoperative TE events. A survival analysis and a Cox regression model was conducted to identify predictors associated with these events., Results: The authors included 651 procedures performed in 591 patients to treat 746 aneurysms. TE events occurred in 38 of the procedures performed (5.8%), causing permanent deficit in 20 patients and death in 4 patients. Eleven cases presented with acute stent thrombosis, 11 with large-vessel occlusion, and 9 with perforator strokes. At a median follow-up of 9.5 months, 73.0% of patients with an ischemic event had a modified Rankin Scale score ≤ 2. Three of the deaths were secondary to occlusion at the basilar trunk and vertebral artery. In patients with TE events in the anterior circulation, 7 of 11 patients with middle cerebral artery occlusion and 9 of 12 patients with internal carotid artery occlusion achieved independence. Time-to-event Cox regression analysis demonstrated that TE events were more frequent in patients exhibiting aspirin resistance (hazard ratio 2.66; 95% CI 1.10-6.70)., Conclusions: TE events after FD result from multiple factors, including age, aneurysm characteristics, aneurysm location, antiplatelet resistance, and procedural factors. In our cohort, we found the highest morbidity for patients with TE events presenting with large-vessel occlusion at the middle cerebral artery, and vertebrobasilar system.

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., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Purpose: Craniotomies for tumor resection can at times result in wound complications which can be devastating in the treatment of neuro-oncological patients. A cranial stair-step technique was recently introduced as an approach to mitigate these complications, especially in this patient population who often exhibit additional risk factors including steroids, chemoradiation, and VEGF inhibitor treatments. This study evaluates our cranial stair-step approach by comparing its postoperative complications using propensity score matching with those of a standard craniotomy wound closure., Methods: A retrospective chart review was conducted on patients with intracranial neoplasms undergoing primary craniotomy at a single institution. Patients with prior craniotomies and less than three months of follow-up were excluded. Analyses were performed using R Studio., Results: 383 patients were included in the study, 139 of whom underwent the stair-step technique while the rest underwent traditional craniotomy closures. The stair-step cohort was older, had higher ASA classes, and had a higher prevalence of coronary artery disease. The stair-step patients were administered fewer steroids before (40.29% vs. 56.56%, p < 0.01) and after surgery (87.05% vs. 94.26%, p = 0.02), fewer immunotherapy (12.95% vs. 20.90%, p = 0.05), but they received more radiation preoperatively (15.11% vs. 8.61%, p = 0.05). They also underwent fewer operations for recurrences and residuals (0.72% vs. 10.66%, p = 0.01). On propensity score matching, we found 111 matched pairs with no differences except follow-up duration (p < 0.01). The stair-step group had fewer soft tissue infections (0% vs. 3.60%, p = 0.04), fewer total wound complications (0% vs. 4.50%, p = 0.02), was operated on less for these complications (0% vs. 3.60%, p = 0.04), and had a shorter length of stay (6 vs. 9 days, p < 0.01). Notably, the average time to wound complication in our cohort was 44 days, well within our exclusion criteria and follow-up duration., Conclusion: The cranial stair-step technique is safe and effective in reducing rates of wound complications and reoperation for neuro-oncologic patients requiring craniotomy., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

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., (Copyright © 2024 Elsevier Inc. All rights reserved.)

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., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The long-term outcomes after stereotactic radiosurgery (SRS) for pediatric brain arteriovenous malformations (AVMs) remain poorly understood given the paucity of longitudinal studies. A systematic review was conducted to pool cumulative incidences for all outcomes., Methods: PubMed, Embase, and Web of Science were queried to systematically extract potential references. The articles relating to AVMs treated via SRS were required to be written in English, involve pediatric patients (<18 years of age), and include a mean follow-up period of >5 years. Individual patient data were obtained to construct a pooled Kaplan-Meier plot on obliteration rates over time., Results: Among the 6 studies involving 1315 pediatric patients averaging a follow-up period of 86.6 months (range, 6-276), AVM obliteration was observed in 66.1% with cumulative probabilities of 48.28% (95% confidence interval [CI], 41.89-54.68), 76.11% (95% CI, 67.50-84.72), 77.48% (95% CI, 66.37-88.59) over 3, 5, and 10 years, respectively. The cumulative incidence of post-SRS hemorrhage, tumors, cysts, and de novo seizures was 7.2%, 0.3%, 1.6%, and 1.5%, respectively. The cumulative incidence of radiation-induced necrosis, edema, radiologic radiation-induced changes (RICs), symptomatic RICs, and permanent RICs were 8.0%, 1.4%, 28.0%, 8.7%, and 4.9%, respectively., Conclusions: Studies assessing long-term outcomes after SRS are moderate in quality and retrospective. Thus, interpretation with caution is advised given the variable degree of loss to follow-up, which suggests that complication rates may be higher than the values stated in the literature. Future prospective studies are needed to validate these findings., (Copyright © 2024 Elsevier Inc. All rights reserved.)

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.

Background: Recent data have identified that certain risk factors for rupture differ between small and larger intracranial aneurysms (IAs). Such differing risk factors make up 5 out of the 6 predictor variables used in the PHASES score, which raises the question on whether IA size has a significant effect on the score's performance., Methods: Patients who were diagnosed with an IA incidentally or due to a subarachnoid hemorrhage between 2015 and 2023 were selected for potential inclusion. The median IA size of the cohort was chosen as the cutoff point to categorize small and large (6 mm). The PHASES score was calculated for all patients, and a receiver operating characteristic curve analysis was performed to evaluate the classification accuracy of PHASES in predicting rupture for small and large IAs., Results: A total of 677 IAs were included. Among the IAs, 400 (58.9%) presented as UIAs and 279 (41.0%) as subarachnoid hemorrhage. The average PHASES score was 2.9 and 6.5 for small (n = 322) and large (n = 355) IAs, respectively. The PHASES score performed significantly lower for predicting rupture in smaller IAs (area under the curve: 0.634) compared with the larger (area under the curve: 0.741) (P = 0.00083)., Conclusions: PHASES was shown to underperform on small IAs. The decision to treat small unruptured IAs remains highly controversial, and the development of a new score to estimate the annual rupture rate while accounting for IA morphology is of great need. Our findings can help encourage future researchers to develop such a score., (Copyright © 2024. Published by Elsevier Inc.)

Background: The collar sign has been previously described as an angiographic indicator of incomplete occlusion after deployment of a pipeline embolization device (PED) for intracranial aneurysms. In the present study, we explore the predictors for a collar sign in aneurysms treated with the PED., Methods: Aneurysms with a collar sign at the initial follow-up angiogram were identified in a retrospective review of single-center data. The predictors of a collar sign were analyzed through univariate and multivariate analyses., Results: A total of 492 cases of cerebral aneurysm treated with the PED were identified. Among them, 53 were found to have a collar sign on the initial follow-up angiogram. Univariate analysis showed that previous treatment of the same aneurysm (odds ratio [OR], 2.46; P = 0.01), a branch vessel from the aneurysm neck or dome (OR, 6.2; P < 0.001), and a smaller aneurysm neck size (OR, 0.75; P = 0.01) were all predictors for the presence of a collar sign. A larger diameter (OR, 0.92; P = 0.06), increased dome/neck ratio (OR, 1.38; P = 0.1), increased aspect ratio (OR, 1.14; 0 P =.17), and previous treatment showed a trend toward an association with a collar sign. However, after multivariate analysis, a branch from the aneurysm neck or dome (OR, 6.23; P < 0.001), aneurysm diameter (OR, 0.75; P = 0.032), an increased dome/neck ratio (OR, 4.62; P = 0.006), and previous treatment were the strongest predictors for a collar sign., Conclusions: The presence of a branch vessel arising from the aneurysm neck or dome, an increased dome/neck ratio, aneurysm diameter, and previous treatment are the strongest predictive factors for a collar sign in the angiographic follow-up of PED-treated aneurysms., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Invited for the cover of this issue are Marek Cigáň, Anna M. Grabarz and co-workers. The image depicts how a non-expert might imagine a "molecular photoswitch". Read the full text of the article at 10.1002/chem.202303509., (© 2024 Wiley-VCH GmbH.)

Triarylhydrazones represent an attractive class of photochromic compounds offering many interesting features including high molar absorptivity, good addressability, and extraordinary thermal stability. In addition, unlike most other hydrazone-based photoswitches, they effectively absorb light above 365 nm. However, previously prepared triaryhydrazones suffer from low quantum yields of the Z→E photoisomerization. Here, we have designed a new subclass of naphthoyl-benzothiazole hydrazones that balance the most beneficial features of previously reported naphthoyl-quinoline and benzoyl-pyridine triarylhydrazones. These preserve the attractive absorption characteristics, exhibit higher thermal stability of the metastable form than the former and enhance the rate of the Z→E photoisomerization compared to the later, as a result of the weakening of the intramolecular hydrogen bonding between the hydrazone hydrogen and the benzothiazole moiety. Introducing the benzothiazole motif extends the tunability of the photochromic behaviour of hydrazone-based switches., (© 2023 Wiley-VCH GmbH.)