Focused update to guidelines for endovascular therapy for emergent large vessel occlusion: basilar artery occlusion patients.

BACKGROUND: Endovascular therapy (EVT) dramatically improves clinical outcomes for patients with anterior circulation emergent large vessel occlusion (ELVO) strokes. With recent publication of two randomized controlled trials in favor of EVT for basilar artery occlusions, the Society of NeuroInterventional Surgery (SNIS) Standards and Guidelines Committee provides this focused update for the existing SNIS guideline, 'Current endovascular strategies for posterior circulation large vessel occlusion stroke.' METHODS: A structured literature review and analysis of studies related to posterior circulation large vessel occlusion (basilar or vertebral artery) strokes treated by EVT was performed. Based on the strength and quality of the evidence, recommendations were made by consensus of the writing committee, with additional input from the full SNIS Standards and Guidelines Committee and the SNIS Board of Directors. RESULTS: Based on the results of the most recent randomized, controlled trials on EVT for basilar or vertebral artery occlusion, the expert panel agreed on the following recommendations. For patients presenting with an acute ischemic stroke due to an acute basilar or vertebral artery occlusion confirmed on CT angiography, National Institutes of Health Stroke Scale (NIHSS) score of ≥6, posterior circulation Alberta Stroke Program Early CT Score (PC-ASPECTS) ≥6, and age 18-89 years: (1) thrombectomy is indicated within 12 hours since last known well (class I, level B-R); (2) thrombectomy is reasonable within 12-24 hours from the last known well (class IIa, level B-R); (3) thrombectomy may be considered on a case by case basis for patients presenting beyond 24 hours since last known well (class IIb, level C-EO). In addition, thrombectomy may be considered on a case by case basis for patients aged <18 years or >89 years on a case by case basis (class IIb, level C-EO). CONCLUSIONS: The indications for EVT of ELVO strokes continue to expand and now include patients with basilar artery occlusion. Further prospective, randomized controlled trials are warranted to elucidate the efficacy and safety of EVT in populations not included in this set of recommendations, and to confirm long term outcomes.

ARISE I Consensus Review on the Management of Intracranial Aneurysms.

BACKGROUND: Intracranial aneurysms (IAs) remain a challenging neurological diagnosis associated with significant morbidity and mortality. There is a plethora of microsurgical and endovascular techniques for the treatment of both ruptured and unruptured aneurysms. There is no definitive consensus as to the best treatment option for this cerebrovascular pathology. The Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts discussed best practices and the most promising approaches to improve the management of brain aneurysms. METHODS: A group of experts from academia, industry, and federal regulators convened to discuss updated clinical trials, scientific research on preclinical system models, management options, screening and monitoring, and promising novel device technologies, aiming to improve the outcomes of patients with IA. RESULTS: Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts suggested the incorporation of artificial intelligence to capture sequential aneurysm growth, identify predictors of rupture, and predict the risk of rupture to guide treatment options. The consensus strongly recommended nationwide systemic data collection of unruptured IA radiographic images for the analysis and development of machine learning algorithms for rupture risk. The consensus supported centers of excellence for preclinical multicenter trials in areas such as genetics, cellular composition, and radiogenomics. Optical coherence tomography and magnetic resonance imaging contrast-enhanced 3T vessel wall imaging are promising technologies; however, more data are needed to define their role in IA management. Ruptured aneurysms are best managed at large volume centers, which should include comprehensive patient management with expertise in microsurgery, endovascular surgery, neurology, and neurocritical care. CONCLUSIONS: Clinical and preclinical studies and scientific research on IA should engage high-volume centers and be conducted in multicenter collaborative efforts. The future of IA diagnosis and monitoring could be enhanced by the incorporation of artificial intelligence and national radiographic and biologic registries. A collaborative effort between academic centers, government regulators, and the device industry is paramount for the adequate management of IA and the advancement of the field.

Outcomes with General Anesthesia Compared to Conscious Sedation for Endovascular Treatment of Medium Vessel Occlusions: Results of an International Multicentric Study.

BACKGROUND: Optimal anesthetic strategy for the endovascular treatment of stroke is still under debate. Despite scarce data concerning anesthetic management for medium and distal vessel occlusions (MeVOs) some centers empirically support a general anesthesia (GA) strategy in these patients. METHODS: We conducted an international retrospective study of MeVO cases. A propensity score matching algorithm was used to mitigate potential differences across patients undergoing GA and conscious sedation (CS). Comparisons in clinical and safety outcomes were performed between the two study groups GA and CS. The favourable outcome was defined as a modified Rankin Scale (mRS) 0-2 at 90 days. Safety outcomes were 90-days mortality and symptomatic intracranial hemorrhage (sICH). Predictors of a favourable outcome and sICH were evaluated with backward logistic regression. RESULTS: After propensity score matching 668 patients were included in the CS and 264 patients in the GA group. In the matched cohort, either strategy CS or GA resulted in similar rates of good functional outcomes (50.1% vs. 48.4%), and successful recanalization (89.4% vs. 90.2%). The GA group had higher rates of 90-day mortality (22.6% vs. 16.5%, p < 0.041) and sICH (4.2% vs. 0.9%, p = 0.001) compared to the CS group. Backward logistic regression did not identify GA vs CS as a predictor of good functional outcome (OR for GA vs CS = 0.95 (0.67-1.35)), but GA remained a significant predictor of sICH (OR = 5.32, 95% CI 1.92-14.72). CONCLUSION: Anaesthetic strategy in MeVOs does not influence favorable outcomes or final successful recanalization rates, however, GA may be associated with an increased risk of sICH and mortality.

Comparison between endovascular and surgical treatment of spinal dural arteriovenous fistulas: a single-center cohort and systematic review.

OBJECTIVE: With recent advancements in minimally invasive techniques, endovascular embolization has gained popularity as a first-line treatment option for spinal dural arteriovenous fistulas (sDAVFs). The authors present their institution's case series of sDAVFs treated endovascularly and surgically, and they performed a systemic review to assess the outcomes of both modalities of treatment. METHODS: The authors conducted a retrospective observational study of 24 consecutive patients with sDAVFs treated between 2013 and 2023. The primary outcome was the rate of occlusion, which was compared between the surgically and endovascularly treated sDAVFs. They also conducted a systemic review of all the literature comparing outcomes of endovascular and surgical treatment of sDAVFs. RESULTS: A total of 24 patients with 24 sDAVFs were studied. The mean patient age was 63.8 ± 15.5 years, and the majority of patients were male (n = 19, 79.2%). Of the 24 patients, 8 (33.3%) received endovascular treatment, 15 (62.5%) received surgical treatment, and 1 (4.2%) patient received both. Complete occlusion at first follow-up was higher in the surgical cohort but did not achieve statistical significance (66.7% vs 25%, p = 0.52). Recurrence was higher in the endovascular cohort (37.5% vs 13.3%, p = 0.3), while the rate of postprocedural complications was higher in the surgical cohort (13.3% vs 0%, p = 0.52); however, neither of these differences was statistically significant. CONCLUSIONS: Endovascular embolization in the management of sDAVFs is an alternative treatment to surgery, whose long-term efficacy is still under investigation. These findings suggest overall comparable outcomes between endovascular and open surgical treatment of sDAVFs. Future studies are needed to determine the role of endovascular embolization in the overall management of sDAVFs.

Comparison of the transarterial, transvenous, and superior ophthalmic vein approaches in the treatment of indirect carotid-cavernous fistulas.

OBJECTIVE: Indirect carotid-cavernous fistulas (CCFs) are abnormal arteriovenous shunting lesions with a highly variable clinical presentation that depends on the drainage pattern. Based on venous drainage, treatment can be either transarterial (TA) or transvenous (TV). The aim of this study was to compare the outcomes of indirect CCF embolization via the TA, TV, and direct superior ophthalmic vein (SOV) approaches. METHODS: The authors conducted a retrospective analysis of 74 patients admitted to their institution from 2010 to 2023 with the diagnosis of 77 indirect CCFs as confirmed on digital subtraction angiography. RESULTS: A total of 74 patients with 77 indirect CCFs were included in this study. Embolization was performed via the TA approach in 4 cases, the TV approach in 50 cases, and the SOV in 23 cases. At the end of the procedure, complete occlusion was achieved in 76 (98.7%) cases. The rate of complete occlusion at the end of the procedure and at last radiological follow-up was significantly higher in the SOV and TV cohorts than in the TA cohort. The rate of recurrence was highest in the TA cohort (25% for TA vs 5.3% for TV vs 0% for SOV, p = 0.68). CONCLUSIONS: The rate of immediate complete occlusion was higher in the TV and SOV cohorts than in the TA cohort while the rate of complete occlusion at final follow-up was highest in the SOV cohort. The SOV approach was significantly associated with higher rates of postoperative complications. Indirect CCFs require careful examination of the fistulous point and the venous drainage to provide the most effective patient-tailored approach.

Clinical relevance of intracranial hemorrhage after thrombectomy versus medical management for large core infarct: a secondary analysis of the SELECT2 randomized trial.

BACKGROUND: The incidence of intracerebral hemorrhage (ICH) and its effect on the outcomes after endovascular thrombectomy (EVT) for patients with large core infarcts have not been well-characterized. METHODS: SELECT2 trial follow-up imaging was evaluated using the Heidelberg Bleeding Classification (HBC) to define hemorrhage grade. The association of ICH with clinical outcomes and treatment effect was examined. RESULTS: Of 351 included patients, 194 (55%) and 189 (54%) demonstrated intracranial and intracerebral hemorrhage, respectively, with a higher incidence in EVT (134 (75%) and 130 (73%)) versus medical management (MM) (60 (35%) and 59 (34%), both P<0.001). Hemorrhagic infarction type 1 (HBC=1a) and type 2 (HBC=1b) accounted for 93% of all hemorrhages. Parenchymal hematoma (PH) type 1 (HBC=1c) and type 2 (HBC=2) were observed in 1 (0.6%) EVT-treated and 4 (2.2%) MM patients. Symptomatic ICH (sICH) (SITS-MOST definition) was seen in 0.6% EVT patients and 1.2% MM patients. No trend for ICH with core volumes (P=0.10) or Alberta Stroke Program Early CT Score (ASPECTS) (P=0.74) was observed. Among EVT patients, the presence of any ICH did not worsen clinical outcome (modified Rankin Scale (mRS) at 90 days: 4 (3-6) vs 4 (3-6); adjusted generalized OR 1.00, 95% CI 0.68 to 1.47, P>0.99) or modify EVT treatment effect (Pinteraction=0.77). CONCLUSIONS: ICH was present in 75% of the EVT population, but PH or sICH were infrequent. The presence of any ICH did not worsen functional outcomes or modify EVT treatment effect at 90-day follow-up. The high rate of hemorrhages overall still represents an opportunity for adjunctive therapies in EVT patients with a large ischemic core.

The natural history of aneurysms incompletely occluded by placement of a flow diverter: a multiinstitutional study.

OBJECTIVE: Treatment of intracranial aneurysms by flow diversion is safe and effective and is increasingly popular. However, the correct treatment paradigm for aneurysms incompletely treated by initial placement of a flow diverter has not been established, nor have the subsequent natural history and occlusion rates of such aneurysms. The authors sought to outline the natural history of such aneurysms, which to date have been considered partially treated. METHODS: The authors retrospectively reviewed consecutive cases from 6 high-volume neurointerventional services, including all cases in which the first follow-up imaging after placement of a flow diverter showed incomplete occlusion of the aneurysm, and for which subsequent clinical and/or radiological follow-up was available. All included patients were treated with the Pipeline Flex embolization device or the Pipeline Flex embolization device with Shield Technology. Subsequent radiographic and clinical outcome data were collected and analyzed using the Kaplan-Meier survival function. RESULTS: A total of 263 patients with persistently patent aneurysms on first follow-up imaging after flow diversion were identified. Of these, 204 had clinical follow-up and 152 had additional imaging follow-up. Of this final cohort, 148 aneurysms were unruptured, and 4 were ruptured. The average aneurysm size by maximum dimension was 10.8 mm. The average recorded follow-up was 27.8 months in the cohort, with some patients followed for as long as 9 years from treatment. Over the course of 403 person-years of follow-up, no delayed aneurysm ruptures were recorded. Both with and without retreatment, aneurysms showed a trend toward progressive occlusion over time. Complications related to device placement were low. CONCLUSIONS: Aneurysms that have been incompletely treated by flow diversion have a benign natural history with progression toward occlusion over time, with or without retreatment.

Use of the pRESET LITE thrombectomy device in combined approach for medium vessel occlusions: A multicenter evaluation.

PURPOSE: Our purpose was to assess the efficacy and safety of the pRESET LITE stent retriever (Phenox, Bochum, Germany), designed for medium vessel occlusion (MeVO) in acute ischemic stroke (AIS) patients with a primary MeVO. METHODS: We performed a retrospective analysis of the MAD MT Consortium, an integration of prospectively maintained databases at 37 academic institutions in Europe, North America, and Asia, of AIS patients who underwent mechanical thrombectomy with the pRESET LITE stent retriever for a primary MeVO. We subcategorized occlusions into proximal MeVOs (segments A1, M2, and P1) vs. distal MeVOs/DMVO (segments A2, M3-M4, and P2). We reviewed patient and procedural characteristics, as well as angiographic and clinical outcomes. RESULTS: Between September 2016 and December 2021, 227 patients were included (50% female, median age 78 [65-84] years), of whom 161 (71%) suffered proximal MeVO and 66 (29%) distal MeVO. Using a combined approach in 96% of cases, successful reperfusion of the target vessel (mTICI 2b/2c/3) was attained in 85% of proximal MeVO and 97% of DMVO, with a median of 2 passes (IQR: 1-3) overall. Periprocedural complications rate was 7%. Control CT at day 1 post-MT revealed a hemorrhagic transformation in 63 (39%) patients with proximal MeVO and 24 (36%) patients with DMVO, with ECASS-PH type hemorrhagic transformations occurring in 3 (1%) patients. After 3 months, 58% of all MeVO and 63% of DMVO patients demonstrated a favorable outcome (mRS 0-2). CONCLUSION: Mechanical thrombectomy using the pRESET LITE in a combined approach with an aspiration catheter appears effective for primary medium vessel occlusions across several centers and physicians.

The Artificial Intelligence Revolution in Stroke Care: A Decade of Scientific Evidence in Review.

BACKGROUND: The emergence of artificial intelligence (AI) has significantly influenced the diagnostic evaluation of stroke and has revolutionized acute stroke care delivery. The scientific evidence evaluating the role of AI, especially in areas of stroke treatment and rehabilitation is limited but continues to accumulate. We performed a systemic review of current scientific evidence evaluating the use of AI in stroke evaluation and care and examined the publication trends during the past decade. METHODS: A systematic search of electronic databases was conducted to identify all studies published from 2012 to 2022 that incorporated AI in any aspect of stroke care. Studies not directly relevant to stroke care in the context of AI and duplicate studies were excluded. The level of evidence and publication trends were examined. RESULTS: A total of 623 studies were examined, including 101 reviews (16.2%), 9 meta-analyses (1.4%), 140 original articles on AI methodology (22.5%), 2 case reports (0.3%), 2 case series (0.3%), 31 case-control studies (5%), 277 cohort studies (44.5%), 16 cross-sectional studies (2.6%), and 45 experimental studies (7.2%). The highest published area of AI in stroke was diagnosis (44.1%) and the lowest was rehabilitation (12%). A 10-year trend analysis revealed a significant increase in AI literature in stroke care. CONCLUSIONS: Most research on AI is in the diagnostic area of stroke care, with a recent noteworthy trend of increased research focus on stroke treatment and rehabilitation.

Microsurgical Clipping of Unruptured Anterior Circulation Aneurysms-A Global Multicenter Investigation of Perioperative Outcomes.

BACKGROUND AND OBJECTIVES: Microsurgical aneurysm repair by clipping continues to be highly important despite increasing endovascular treatment options, especially because of inferior occlusion rates. This study aimed to present current global microsurgical treatment practices and to identify risk factors for complications and neurological deterioration after clipping of unruptured anterior circulation aneurysms. METHODS: Fifteen centers from 4 continents participated in this retrospective cohort study. Consecutive patients who underwent elective microsurgical clipping of untreated unruptured intracranial aneurysm between January 2016 and December 2020 were included. Posterior circulation aneurysms were excluded. Outcome parameters were postsurgical complications and neurological deterioration (defined as decline on the modified Rankin Scale) at discharge and during follow-up. Multivariate regression analyses were performed adjusting for all described patient characteristics. RESULTS: Among a total of 2192 patients with anterior circulation aneurysm, complete occlusion of the treated aneurysm was achieved in 2089 (95.3%) patients at discharge. The occlusion rate remained stable (94.7%) during follow-up. Regression analysis identified hypertension (P < .02), aneurysm diameter (P < .001), neck diameter (P < .05), calcification (P < .01), and morphology (P = .002) as preexisting risk factors for postsurgical complications and neurological deterioration at discharge. Furthermore, intraoperative aneurysm rupture (odds ratio 2.863 [CI 1.606-5.104]; P < .01) and simultaneous clipping of more than 1 aneurysm (odds ratio 1.738 [CI 1.186-2.545]; P < .01) were shown to be associated with an increased risk of postsurgical complications. Yet, none of the surgical-related parameters had an impact on neurological deterioration. Analyzing volume-outcome relationship revealed comparable complication rates (P = .61) among all 15 participating centers. CONCLUSION: Our international, multicenter analysis presents current microsurgical treatment practices in patients with anterior circulation aneurysms and identifies preexisting and surgery-related risk factors for postoperative complications and neurological deterioration. These findings may assist in decision-making for the optimal therapeutic regimen of unruptured anterior circulation aneurysms.

Causes and Predictors of 30-Day Readmission in Patients With Stroke Undergoing Mechanical Thrombectomy: A Large Single-Center Experience.

BACKGROUND AND OBJECTIVES: The 30-day readmission rate has emerged as a metric of quality care and is associated with increased health care expenditure. We aim to identify the rate and causes of 30-day readmission after mechanical thrombectomy and provide the risk factors of readmission to highlight high-risk patients who may require closer care. METHODS: This is a retrospective study from a prospectively maintained database of 703 patients presenting for mechanical thrombectomy between 2017 and 2023. All patients who presented with a stroke and underwent a mechanical thrombectomy were included in this study. Patients who were deceased on discharge were excluded from this study. RESULTS: Our study comprised 703 patients, mostly female (n = 402, 57.2%) with a mean age of 70.2 years ±15.4. The most common causes of readmission were cerebrovascular events (stroke [n = 21, 36.2%], intracranial hemorrhage [n = 9, 15.5%], and transient ischemic attack [n = 1, 1.7%]).Other causes of readmission included cardiovascular events (cardiac arrest [n = 4, 6.9%] and bradycardia [n = 1, 1.7%]), infection (wound infection postcraniectomy [n = 3, 5.2%], and pneumonia [n = 1, 1.7%]). On multivariate analysis, independent predictors of 30-day readmission were history of smoking (odds ratio [OR]: 2.2, 95% CI: 1.1-4.2) P = .01), distal embolization (OR: 3.2, 95% CI: 1.1-8.7, P = .03), decompressive hemicraniectomy (OR: 9.3, 95% CI: 3.2-27.6, P < .01), and intracranial stent placement (OR: 4.6, 95% CI: 2.4-8.7) P < .01). CONCLUSION: In our study, the rate of 30-day readmission was 8.3%, and the most common cause of readmission was recurrent strokes. We identified a history of smoking, distal embolization, decompressive hemicraniectomy, and intracranial stenting as independent predictors of 30-day readmission in patients with stroke undergoing mechanical thrombectomy.

Repeat thrombectomy after large vessel re-occlusion: a propensity score matched analysis of technical and clinical outcomes.

BACKGROUND: Endovascular thrombectomy (EVT) remains the standard of care for acute large vessel occlusion (LVO) stroke. However, the safety and efficacy of repeat thrombectomy (rEVT) in recurrent LVO remains unclear. This study uses a large real-world patient cohort to study technical and clinical outcomes after rEVT. METHODS: This is a retrospective cohort study including patients who underwent thrombectomy between January 2013 and December 2022. Data were included from 21 comprehensive stroke centers globally through the Stroke Thrombectomy and Aneurysm Registry (STAR). Patients undergoing single EVT or rEVT within 30 days of LVO stroke were included in the study. Propensity score matching was used to compare patients undergoing single EVT versus rEVT. RESULTS: Out of a total of 7387 patients who underwent thrombectomy for LVO stroke, 90 (1.2%) patients underwent rEVT for the same vascular territory within 30 days. The median (IQR) time to re-occlusion was 2 (1-7) days. Compared with a matched cohort of patients undergoing a single EVT procedure, patients undergoing rEVT had a comparable rate of good functional outcome and mortality rate, but a higher rate of symptomatic intracranial hemorrhage (sICH). There was a significant reduction in the National Institutes of Health Stroke Scale (NIHSS) score of patients who underwent rEVT at discharge compared with baseline (-4.8±11.4; P=0.006). The rate of successful recanalization was similar in the single thrombectomy and rEVT groups (78% vs 80%, P=0.171) and between index and rEVT performed on the same patient (79% vs 80%; P=0.593). CONCLUSION: Short-interval rEVT is associated with an improvement in the NIHSS score following large vessel re-occlusion. Compared with single thrombectomy, there was a higher rate of sICH with rEVT, but without a significant impact on rates of functional independence or mortality.

First United States multicenter experience with the new-generation FRED X surface-modified flow diversion stent: feasibility, safety, and short-term efficacy.

OBJECTIVE: Flow diversion created a paradigm shift in the treatment of intracranial aneurysms. The new flow redirection endoluminal device with X technology (FRED X) is the latest update of the recent Food and Drug Administration-approved FRED. The FRED X is engineered to reduce material thrombogenicity and enhance vessel healing. In this study, the authors aimed to evaluate the feasibility and early safety and efficacy of the new FRED X. METHODS: The authors retrospectively collected and analyzed data from patients who had undergone flow diversion with the new FRED X at four tertiary cerebrovascular centers in the United States from February 2022 through July 2022. RESULTS: Forty-four patients with 45 aneurysms treated using 46 devices comprised the overall study cohort and were divided into two groups: 39 patients with unruptured aneurysms and 5 patients with ruptured aneurysms. The mean patient age was 57.7 ± 9.1 years, and most patients were female (84%). Ninety-one percent of the aneurysms were saccular, with the majority (93%) located in the anterior circulation, specifically the posterior communicating (27%) and carotid ophthalmic (27%) territories. The mean maximum aneurysm diameter was 5.6 ± 4.6 mm, and 20% of the lesions had been previously treated. The mean procedure time was 61.6 minutes, with a mean cumulative fluoroscopy time of 24.6 minutes. Additionally, 7% of the lesions received adjunct treatment. Stent placement was successful in 100% of cases, achieving good wall apposition and complete neck coverage. Further, immediate aneurysm contrast stasis > 90% was observed in 61% of cases. Symptomatic postoperative complications occurred in 3 patients in the unruptured cohort and 1 patient in the ruptured cohort. All patients in the study were discharged on dual antiplatelet regimens with a modified Rankin Scale score of 0. At 6 months after treatment, 89% of cases had adequate occlusion, with < 6% of cases having asymptomatic in-stent stenosis. All patients had excellent functional outcomes. CONCLUSIONS: FRED X for the treatment of an intracranial aneurysm is technically feasible alone or in conjunction with intrasaccular embolization. In addition, the study results showed very promising early safety and efficacy. Follow-up studies should establish the long-term safety and efficacy profiles of this new stent.

Global Outcomes for Microsurgical Clipping of Unruptured Intracranial Aneurysms: A Benchmark Analysis of 2245 Cases.

BACKGROUND AND OBJECTIVES: Benchmarks represent the best possible outcome and help to improve outcomes for surgical procedures. However, global thresholds mirroring an optimal and reachable outcome for microsurgical clipping of unruptured intracranial aneurysms (UIA) are not available. This study aimed to define standardized outcome benchmarks in patients who underwent clipping of UIA. METHODS: A total of 2245 microsurgically treated UIA from 15 centers were analyzed. Patients were categorized into low- ("benchmark") and high-risk ("nonbenchmark") patients based on known factors affecting outcome. The benchmark was defined as the 75th percentile of all centers' median scores for a given outcome. Benchmark outcomes included intraoperative (eg, duration of surgery, blood transfusion), postoperative (eg, reoperation, neurological status), and aneurysm-related factors (eg, aneurysm occlusion). Benchmark cutoffs for aneurysms of the anterior communicating/anterior cerebral artery, middle cerebral artery, and posterior communicating artery were determined separately. RESULTS: Of the 2245 cases, 852 (37.9%) patients formed the benchmark cohort. Most operations were performed for middle cerebral artery aneurysms (53.6%), followed by anterior communicating and anterior cerebral artery aneurysms (25.2%). Based on the results of the benchmark cohort, the following benchmark cutoffs were established: favorable neurological outcome (modified Rankin scale ≤2) ≥95.9%, postoperative complication rate ≤20.7%, length of postoperative stay ≤7.7 days, asymptomatic stroke ≤3.6%, surgical site infection ≤2.7%, cerebral vasospasm ≤2.5%, new motor deficit ≤5.9%, aneurysm closure rate ≥97.1%, and at 1-year follow-up: aneurysm closure rate ≥98.0%. At 24 months, benchmark patients had a better score on the modified Rankin scale than nonbenchmark patients. CONCLUSION: This study presents internationally applicable benchmarks for clinically relevant outcomes after microsurgical clipping of UIA. These benchmark cutoffs can serve as reference values for other centers, patient registries, and for comparing the benefit of other interventions or novel surgical techniques.

Direct Versus Indirect Revascularization for Moyamoya: a Large Multicenter Study.

BACKGROUND: Moyamoya is a chronic occlusive cerebrovascular disease of unknown etiology causing neovascularization of the lenticulostriate collaterals at the base of the brain. Although revascularization surgery is the most effective treatment for moyamoya, there is still no consensus on the best surgical treatment modality as different studies provide different outcomes. OBJECTIVE: In this large case series, we compare the outcomes of direct (DR) and indirect revascularisation (IR) and compare our results to the literature in order to reflect on the best revascularization modality for moyamoya. METHODS: We conducted a multicenter retrospective study in accordance with the Strengthening the Reporting of Observational studies in Epidemiology guidelines of moyamoya affected hemispheres treated with DR and IR surgeries across 13 academic institutions predominantly in North America. All patients who underwent surgical revascularization of their moyamoya-affected hemispheres were included in the study. The primary outcome of the study was the rate of symptomatic strokes. RESULTS: The rates of symptomatic strokes across 515 disease-affected hemispheres were comparable between the two cohorts (11.6% in the DR cohort vs 9.6% in the IR cohort, OR 1.238 (95% CI 0.651 to 2.354), p=0.514). The rate of total perioperative strokes was slightly higher in the DR cohort (6.1% for DR vs 2.0% for IR, OR 3.129 (95% CI 0.991 to 9.875), p=0.052). The rate of total follow-up strokes was slightly higher in the IR cohort (8.1% vs 6.6%, OR 0.799 (95% CI 0.374 to 1.709) p=0.563). CONCLUSION: Since both modalities showed comparable rates of overall total strokes, both modalities of revascularization can be performed depending on the patient's risk assessment.

Resuming Anticoagulants in Patients With Intracranial Hemorrhage: A Meta-Analysis and Literature Review.

BACKGROUND AND OBJECTIVES: Intracerebral hemorrhage (ICH) is one of the most disabling cerebrovascular events. Several studies have discussed oral anticoagulant (OAC)-related ICH; however, the optimal timing of resuming OAC in patients with ICH is still a dilemma. In this literature review/meta-analysis, we will summarize, discuss, and provide the results of studies pertaining to OAC resumption in patients with ICH. METHODS: Using PubMed, Ovid Medline, and Web science, a systemic literature review was performed in accordance with the Preferred Reporting Items for Systemic Reviews and Meta-Analyses statement on December 20, 2022. Inclusion criteria for the meta-analysis were all studies reporting mean, median, and standard deviation for the duration of anticoagulants resumption after ICH. Thirteen studies met the above criteria and were included in the meta-analysis. RESULTS: Of the 271 articles found in the literature, pooled analysis was performed in 13 studies that included timing of OAC resumption after ICH. The pooled mean duration to OAC resumption after the index ICH was 31 days (95% CI: 13.7-48.3). There was significant variation among the mean duration to OAC resumption reported by the studies as observed in the heterogeneity test ( P -value ≈0). CONCLUSION: Based on our meta-analysis, the average time of resuming OAC in patients with ICH is around 30 days. Several factors including the type of intracranial hemorrhage, the type of OAC, and the indication for OACs should be taken into consideration for future studies to try and identify the best time to resume OAC in patients with ICH.

Comparison of PED/PED Flex and PED Shield in the treatment of unruptured intracerebral aneurysms.

OBJECTIVE: The object of this study was to compare the efficacy and safety profile of the Pipeline embolization device (PED)/Pipeline Flex embolization device (PED Flex) with that of the Pipeline Flex embolization device with Shield Technology (PED Shield). After introducing the first-generation PED and the second-generation PED Flex with its updated delivery system, the PED Shield was launched with a synthetic layer of phosphorylcholine surface modification to reduce thrombogenicity. METHODS: This is a retrospective review of unruptured aneurysms treated with PED/PED Flex versus PED Shield between 2017 and 2022 at the authors' institution. Patients with ruptured aneurysms, adjunctive treatment, failed flow diverter deployment, and prior treatment of the target aneurysm were excluded. Baseline characteristics were collected for all patients, including age, sex, past medical history (hypertension, hyperlipidemia, diabetes mellitus), smoking status, aneurysm location, and aneurysm dimensions (neck, width, height) and morphology (saccular, nonsaccular). The primary outcome was procedural and periprocedural complication rates. RESULTS: The study cohort comprised 200 patients with 200 aneurysms, including 150 aneurysms treated with the PED/PED Flex and 50 treated with the PED Shield. With respect to intraprocedural and periprocedural complications, length of stay, length of follow-up, and functional outcome at discharge, there was no significant difference between the two cohorts. At the midterm follow-up, the rate of in-stent stenosis (PED/PED Flex: 14.2% vs PED Shield: 14.6%, p = 0.927), aneurysm occlusion (complete occlusion: 79.5% vs 80.5%, respectively; neck remnant: 4.7% vs 12.2%; dome remnant: 15.7% vs 7.3%; p = 0.119), and the need for retreatment (5.3% vs 0%, p = 0.097) were comparable between the two cohorts. CONCLUSIONS: This study suggests that, as compared to first- and second-generation PED and PED Flex, the third-generation PED Shield offers similar rates of complications, aneurysm occlusion, and in-stent stenosis at the midterm follow-up.

Women in neurosurgery: a cross-sectional demographic study of female neurosurgery residents in the United States.

OBJECTIVE: Over the past several decades, the number of women applying to medical school has increased significantly. However, parallel recruitment and retention of women in the field of neurosurgery continues to lag. The aim of this study was to identify the ratio and trend of female neurosurgery residents to the total number of residents during the past 7 years across all US neurosurgery residency programs. METHODS: The authors conducted a cross-sectional demographic study investigating the ratio of female neurosurgery residents to the total number of neurosurgery residents across US neurosurgical programs from 2016 to 2022. Using the Fellowship and Residency Electronic Interactive Database, all neurosurgical residency programs in the US were collected. Data were further divided into postgraduate years 1-7 to dissect the data collection per residency year. One hundred fourteen programs were included in the study. RESULTS: The number of female neurosurgery residents was 71 (29.8%) in 2022, 58 (25.2%) in 2021, 65 (27.9%) in 2020, 62 (27.3%) in 2019, 46 (21.4%) in 2018, 33 (15.2%) in 2017, and 34 (15.9%) in 2016. The trend line showed a significant increase using the Mann-Kendall test (p = 0.035). The total number of international medical graduate (IMG) female neurosurgery residents was 3 (4.2%) in 2022, 4 (6.9%) in 2021, 3 (4.6%) in 2020, 1 (1.6%) in 2019, 1 (2.2%) in 2018, 1 (3%) in 2017, and 2 (5.9%) in 2016. CONCLUSIONS: The number of women matching into neurosurgery residency programs is modestly increasing, especially for IMG women. Future steps toward fewer gender disparities should focus on career advancement and leadership diversification in organized and academic neurosurgery.

The Enterprise stent still useful after all these years.

BACKGROUND: The Enterprise stent (Codman Neuro, Massachusetts, USA) received Food and Drug Administration (FDA) approval in 2007 for stent-assisted coiling (SAC). Since its introduction, newer stents and devices for aneurysm treatment have been developed resulting in a shift in the utilization of this stent from SAC to other off-label indications. OBJECTIVE: To describe our experience with the Enterprise stent being used for SAC and other off-label indications. METHODS: This is a multi-center retrospective review of the use of the Enterprise stent between 2018 and 2023. All patients in which the Enterprise stent was successfully deployed were included in the study. RESULTS: Our study cohort comprised of 194 patients, mostly females (n = 112, 57.7%), with a mean age of 63.2 years ± 14.3. The Enterprise stent was used for SAC in only 24 (12.4%) patients and was used for rescue stenting in stroke in 101 patients (52.1%), treatment of intracranial stenosis in 53 patients (27.3%), treatment of in-stent stenosis in 1 patient (0.5%), and for treatment of dissections in 15 patients (7.7%). From 2018 to 2023, the use of Enterprise stents for SAC significantly decreased (p < 0.0001) while the use of Enterprise stents for non-SAC purposes was insignificantly variable (p = 0.05). CONCLUSION: Our study shows that the Enterprise stent remains a reliable tool in neuroendovascular procedures, even if its original intended use has been supplanted by other devices.