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.

Middle meningeal artery patency after surgical evacuation for chronic subdural hematoma.

BACKGROUND: Chronic subdural hematoma (CSDH) often requires surgical evacuation, but recurrence rates remain high. Middle meningeal artery (MMA) embolization (MMAE) has been proposed as an alternative or adjunct treatment. There is concern that prior surgery might limit patency, access, penetration, and efficacy of MMAE, such that some recent trials excluded patients with prior craniotomy. However, the impact of prior open surgery on MMA patency has not been studied. METHODS: A retrospective analysis was conducted on patients who underwent MMAE for cSDH (2019-2022), after prior surgical evacuation or not. MMA patency was assessed using a six-point grading scale. RESULTS: Of the 109 MMAEs (84 patients, median age 72 years, 20.2% females), 58.7% were upfront MMAEs, while 41.3% were after prior surgery (20 craniotomies, 25 burr holes). Median hematoma thickness was 14 mm and midline shift 3 mm. Hematoma thickness reduction, surgical rescue, and functional outcome did not differ between MMAE subgroups and were not affected by MMA patency or total area of craniotomy or burr-holes. MMA patency was reduced in the craniotomy group only, specifically in the distal portion of the anterior division (p = 0.005), and correlated with craniotomy area (p < 0.001). CONCLUSION: MMA remains relatively patent after burr-hole evacuation of cSDH, while craniotomy typically only affects the frontal-distal division. However, MMA patency, evacuation method, and total area do not affect outcomes. These findings support the use of MMAE regardless of prior surgery and may influence future trial inclusion/exclusion criteria. Further studies are needed to optimize the timing and techniques for MMAE in cSDH management.

Complex intracranial aneurysms: a DELPHI study to define associated characteristics.

PURPOSE: Intracranial aneurysms present significant health risks, as their rupture leads to subarachnoid haemorrhage, which in turn has high morbidity and mortality rates. There are several elements affecting the complexity of an intracranial aneurysm. However, criteria for defining a complex intracranial aneurysm (CIA) in open surgery and endovascular treatment could differ, and actually there is no consensus on the definition of a "complex" aneurysm. This DELPHI study aims to assess consensus on variables defining a CIA. METHODS: An international panel of 50 members, representing various specialties, was recruited to define CIAs through a three-round Delphi process. The panelists participated in surveys with Likert scale responses and open-ended questions. Consensus criteria were established to determine CIA variables, and statistical analysis evaluated consensus and stability. RESULTS: In open surgery, CIAs were defined by fusiform or blister-like shape, dissecting aetiology, giant size (≥ 25 mm), broad neck encasing parent arteries, extensive neck surface, wall calcification, intraluminal thrombus, collateral branch from the sac, location (AICA, SCA, basilar), vasospasm context, and planned bypass (EC-IC or IC-IC). For endovascular treatment, CIAs included giant size, very wide neck (dome/neck ratio ≤ 1:1), and collateral branch from the sac. CONCLUSIONS: The definition of aneurysm complexity varies by treatment modality. Since elements related to complexity differ between open surgery and endovascular treatment, these consensus criteria of CIAs could even guide in selecting the best treatment approach.

mTORC1 Inhibitor Rapamycin Inhibits Growth of Cerebral Cavernous Malformation in Adult Mice.

BACKGROUND: Cerebral cavernous malformations (CCMs) are vascular malformations that frequently cause stroke. CCMs arise due to loss of function in one of the genes that encode the CCM complex, a negative regulator of MEKK3-KLF2/4 signaling in vascular endothelial cells. Gain-of-function mutations in PIK3CA (encoding the enzymatic subunit of the PI3K (phosphoinositide 3-kinase) pathway associated with cell growth) synergize with CCM gene loss-of-function to generate rapidly growing lesions. METHODS: We recently developed a model of CCM formation that closely reproduces key events in human CCM formation through inducible CCM loss-of-function and PIK3CA gain-of-function in mature mice. In the present study, we use this model to test the ability of rapamycin, a clinically approved inhibitor of the PI3K effector mTORC1, to treat rapidly growing CCMs. RESULTS: We show that both intraperitoneal and oral administration of rapamycin arrests CCM growth, reduces perilesional iron deposition, and improves vascular perfusion within CCMs. CONCLUSIONS: Our findings further establish this adult CCM model as a valuable preclinical model and support clinical testing of rapamycin to treat rapidly growing human CCMs.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: Predictors of Clinical and Radiographic Failure from 636 Embolizations.

Background Knowledge regarding predictors of clinical and radiographic failures of middle meningeal artery (MMA) embolization (MMAE) treatment for chronic subdural hematoma (CSDH) is limited. Purpose To identify predictors of MMAE treatment failure for CSDH. Materials and Methods In this retrospective study, consecutive patients who underwent MMAE for CSDH from February 2018 to April 2022 at 13 U.S. centers were included. Clinical failure was defined as hematoma reaccumulation and/or neurologic deterioration requiring rescue surgery. Radiographic failure was defined as a maximal hematoma thickness reduction less than 50% at last imaging (minimum 2 weeks of head CT follow-up). Multivariable logistic regression models were constructed to identify independent failure predictors, controlling for age, sex, concurrent surgical evacuation, midline shift, hematoma thickness, and pretreatment baseline antiplatelet and anticoagulation therapy. Results Overall, 530 patients (mean age, 71.9 years ± 12.8 [SD]; 386 men; 106 with bilateral lesions) underwent 636 MMAE procedures. At presentation, the median CSDH thickness was 15 mm and 31.3% (166 of 530) and 21.7% (115 of 530) of patients were receiving antiplatelet and anticoagulation medications, respectively. Clinical failure occurred in 36 of 530 patients (6.8%, over a median follow-up of 4.1 months) and radiographic failure occurred in 26.3% (137 of 522) of procedures. At multivariable analysis, independent predictors of clinical failure were pretreatment anticoagulation therapy (odds ratio [OR], 3.23; P = .007) and an MMA diameter less than 1.5 mm (OR, 2.52; P = .027), while liquid embolic agents were associated with nonfailure (OR, 0.32; P = .011). For radiographic failure, female sex (OR, 0.36; P = .001), concurrent surgical evacuation (OR, 0.43; P = .009), and a longer imaging follow-up time were associated with nonfailure. Conversely, MMA diameter less than 1.5 mm (OR, 1.7; P = .044), midline shift (OR, 1.1; P = .02), and superselective MMA catheterization (without targeting the main MMA trunk) (OR, 2; P = .029) were associated with radiographic failure. Sensitivity analyses retained these associations. Conclusion Multiple independent predictors of failure of MMAE treatment for chronic subdural hematomas were identified, with small diameter (<1.5 mm) being the only factor independently associated with both clinical and radiographic failures. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Chaudhary and Gemmete in this issue.

Postoperative de novo epilepsy after resection of brain arteriovenous malformations: A national database study of 536 patients.

OBJECTIVE: We aimed to assess the incidence and risk factors for de novo epilepsy after arteriovenous malformation (AVM) resection and compare them with a nonresection cohort after propensity score matching, utilizing a national database. METHODS: Utilizing the TriNetX Research Network, we queried cases from January 1, 2004 to March 1, 2022. We included patients of all ages who underwent supratentorial AVM resection, presenting without seizures on or before surgery and without being on antiseizure medications at least 1 day before surgery. The primary outcome was seizures manifesting at least 6 weeks after surgery. Patient characteristics and outcomes were compared between the cohorts with and without postoperative epilepsy. Further cohorts were created to compare cohorts with and without embolization or rupture. After propensity score matching, we compared an additional cohort of patients with an AVM diagnosis who did not undergo resection. RESULTS: Of the 536 patients (mean age = 38.9 ± 19.6, 52% females) presenting without seizure who underwent AVM resection, 99 (18.5%) developed de novo epilepsy, with a 1-year cumulative incidence of 13.8%. Patients with epilepsy had higher rates of intracerebral hemorrhage, and intracerebral hemorrhage was less common in the embolization cohort. Patients in the ruptured cohort were older and more often males. After propensity score matching with 18 588 patients with AVM diagnosis but no resection, each group consisted of 529 patients, and de novo epilepsy at 1 year was significantly higher in the AVM resection cohort compared to the nonresection cohort (11.5% vs. 3.4%, p < .001). SIGNIFICANCE: This analysis of 536 patients provides evidence that de novo epilepsy after brain AVM resection occurs at a 1-year cumulative incidence of 13.8%, with a total of 19.4% developing de novo epilepsy. Intracerebral hemorrhage was inconsistently associated with postoperative de novo epilepsy. De novo epilepsy was significantly less frequent after AVM diagnosis without resection.

Safety and efficacy of the p48 MW and p64 flow modulation devices: a systematic review and meta-analysis.

OBJECTIVE: Flow diverters (FDs) have demonstrated increasing safety and efficacy in treating various types of intracranial aneurysms. Although the underlying mechanism of action of all FDs is similar, differences are noted in their intrinsic characteristics, materials, and deployment techniques. The p64 flow modulation device (p64) and the newer p48 movable wire flow modulation device (p48 MW) are not yet available in the US but have been increasingly used mainly in Europe, demonstrating optimistic results. The authors performed a systematic review and meta-analysis of the literature to evaluate the safety and efficacy of the p64 and p48 MW FDs. METHODS: A literature review (between January 1960 and November 2022) of the PubMed, Scopus, Embase, Web of Science, and Cochrane Central Register of Controlled Trials databases was conducted. The primary efficacy outcome was the proportion of complete angiographic occlusion at last follow-up. Complete occlusion was defined as Raymond-Roy class 1 and O'Kelly-Marotta grade D. The primary safety outcomes were the composite safety rate of ischemic and hemorrhagic events (intra- and postprocedure) and the all-cause mortality rate. Data were analyzed using a random-effects proportions meta-analysis, and statistical heterogeneity was assessed. RESULTS: Twenty studies with 1781 patients harboring 1957 aneurysms were included in the analysis. Seventeen studies were conducted in Europe. Sixteen studies evaluated the performance of the p64 (MW). Patient ages ranged between 20 and 89 years, and most were female (78.7%). Aneurysm size ranged between 1 and 50 mm. Most aneurysms were unruptured (92.8%) and in the anterior circulation (93.1%). Single antiplatelet therapy pre- and postprocedure was used in 2 studies. Follow-up ranged from 2 to 14.5 months. For the p64 and p48 MW, complete angiographic occlusion rates were 77% (95% CI 68%-85%) and 67% (95% CI 49%-81%), adjunctive coil usage rates were 7% (95% CI 4%-12%) and 4% (95% CI 0%-24%), primary safety composite rates were 2% (95% CI 1%-4%) and 3% (95% CI 1%-11%), and mortality rates were 0.49% (95% CI 0%-1%) and 2% (95% CI 1%-6%), respectively. CONCLUSIONS: The p64 and p48 MW have primarily been used in Europe thus far. This analysis found that both devices have an acceptable efficacy and favorable safety profile. However, further studies are needed to evaluate the efficacy and safety of prescribing a single antiplatelet regimen after implantation of the newer-generation FDs with antithrombotic coating surface modification.

Safety and efficacy of the Pipeline Flex embolization device with Shield Technology for the acute treatment of ruptured internal carotid artery pseudoaneurysms: a multi-institution case series.

OBJECTIVE: Ruptured blister, dissecting, and iatrogenic pseudoaneurysms are rare pathologies that pose significant challenges from a treatment standpoint. Endovascular treatment via flow diversion represents an increasingly popular option; however, drawbacks include the requirement for dual antiplatelet therapy and the potential for thromboembolic complications, particularly acute complications in the ruptured setting. The Pipeline Flex embolization device with Shield Technology (PED-Shield) offers reduced material thrombogenicity, which may aid in the treatment of ruptured internal carotid artery pseudoaneurysms. METHODS: The authors conducted a multi-institution, retrospective case series to determine the safety and efficacy of PED-Shield for the treatment of ruptured blister, dissecting, and iatrogenic pseudoaneurysms of the internal carotid artery. Clinical, radiographic, treatment, and outcomes data were collected. RESULTS: Thirty-three patients were included in the final analysis. Seventeen underwent placement of a single device, and 16 underwent placement of two devices. No thromboembolic complications occurred. Four patients were maintained on aspirin alone, and all others were treated with long-term dual antiplatelet therapy. Among patients with 3-month follow-up, 93.8% had a modified Rankin Scale score of 0-2. Complete occlusion at follow-up was observed in 82.6% of patients. CONCLUSIONS: PED-Shield represents a new option for the treatment of ruptured blister, dissecting, and iatrogenic pseudoaneurysms of the internal carotid artery. The reduced material thrombogenicity appeared to improve the safety of the PED-Shield device, as this series demonstrated no thromboembolic complications even among patients treated with only single antiplatelet therapy. The efficacy of PED-Shield reported in this series, particularly with placement of two devices, demonstrates its potential as a first-line treatment option for these pathologies.

Non-surgical management of chronic subdural hematoma: insights and future perspectives from an international survey including neurosurgeons from 90 countries worldwide.

BACKGROUND: Chronic subdural hematoma (cSDH) is one of the most common neurosurgical conditions. Although surgical evacuation is still the gold standard for treatment, recent advances have led to the development of other management strategies, such as medical therapies and endovascular middle meningeal artery (MMA) embolization. Through this international survey, we investigated the global trends in cSDH management, focusing on medical and endovascular treatments. DESIGN AND PARTICIPANTS: A 14-question, web-based, anonymous survey was distributed to neurosurgeons worldwide. RESULTS: Most responders do not perform MMA embolization (69.5%) unless for specific indications (29.6%). These indications include residual cSDH after surgical evacuation (58.9%) or cSDH in patients on antiplatelet medications to avoid surgical evacuation (44.8%). Survey participants from teaching versus non-teaching hospitals (p = 0.002), public versus private hospitals (p = 0.022), and Europe versus other continents (p < 0.001) are the most users of MMA embolization. A large number of participants (51%) declare they use a conservative/medical approach, mainly to avoid surgery in patients with small cSDH (74.8%). CONCLUSIONS: This survey highlights the current trends of cSDH management, focusing on conservative and MMA embolization treatment strategies. Most responders prefer a conservative approach for patients with small cSDHs not requiring surgical evacuation. However, in higher-risk scenarios such as residual hematomas after surgery or patients on antiplatelet medications, MMA embolization is regarded as a reasonable option by participants. Future studies should clarify the indications of MMA embolization, including appropriate patient selection and efficacy as a stand-alone procedure.

Patient sentiment regarding stroke: Analysis of 2,992 social media posts.

INTRODUCTION: Social media reflects personalized sentiment toward disease and increasingly impacts perceptions of treatment options. This study aims to assess patients experience with and perception of stroke through an analysis of social media posts. METHODS: A variety of terms ("stroke", "stroke survivor", "stroke rehab", "stroke recovery") were used to search for possible qualified posts on Twitter and Instagram. Twitter posts containing "#stroke" and "@stroke" were identified, yielding 2,506 Twitter posts relating to the patient's own experience. Four hundred sixty-eight public Instagram posts marked under "#stroke" and "@stroke," including direct references to the patient's own experience, were analyzed. First vs. recurrent stroke was identified when possible. The posts were coded for themes relating to patient experience with the disease. RESULTS: The most common Twitter theme was raising stroke awareness (23.4 %), while spreading positivity was the most common Instagram theme (66.7 %). Most Twitter posts (93.9 %) were from patients experiencing their first stroke, with only 6.1 % of the posts being about recurrent strokes. Women created the majority of Instagram (75.7 %) and Twitter (77.3 %) posts. Men were more likely to discuss mobility/functional outcomes (p = 0.001) and survival/death (p = 0.014), while women were more likely to recount symptoms (p = 0.014), depression (p = 0.002), fear (p<0.001), and mental health (p = 0.006). CONCLUSION: Stroke patients most often describe their quality of life and discuss raising awareness via social media. Men and women differ in the most commonly shared aspects of their stroke experience. Gauging social media sentiment may guide physicians toward better counseling and psychosocial management of stroke patients.

Herniation World Federation of Neurosurgical Societies Scale Improves Prediction of Outcome in Patients With Poor-Grade Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Favorable outcomes are seen in up to 50% of patients with World Federation of Neurosurgical Societies (WFNS) grade V aneurysmal subarachnoid hemorrhage. Therefore, the usefulness of the current WFNS grading system for identifying the worst scenarios for clinical studies and for making treatment decisions is limited. We previously modified the WFNS scale by requiring positive signs of brain stem dysfunction to assign grade V. This study aimed to validate the new herniation WFNS grading system in an independent prospective cohort. METHODS: We conducted an international prospective multicentre study in poor-grade aneurysmal subarachnoid hemorrhage patients comparing the WFNS classification with a modified version-the herniation WFNS scale (hWFNS). Here, only patients who showed positive signs of brain stem dysfunction (posturing, anisocoric, or bilateral dilated pupils) were assigned hWFNS grade V. Outcome was assessed by modified Rankin Scale score 6 months after hemorrhage. The primary end point was the difference in specificity of the WFNS and hWFNS grading with respect to poor outcomes (modified Rankin Scale score 4-6). RESULTS: Of the 250 patients included, 237 reached the primary end point. Comparing the WFNS and hWFNS scale after neurological resuscitation, the specificity to predict poor outcome increased from 0.19 (WFNS) to 0.93 (hWFNS) (McNemar, P<0.001) whereas the sensitivity decreased from 0.88 to 0.37 (P<0.001), and the positive predictive value from 61.9 to 88.3 (weighted generalized score statistic, P<0.001). For mortality, the specificity increased from 0.19 to 0.93 (McNemar, P<0.001), and the positive predictive value from 52.5 to 86.7 (weighted generalized score statistic, P<0.001). CONCLUSIONS: The identification of objective positive signs of brain stem dysfunction significantly improves the specificity and positive predictive value with respect to poor outcome in grade V patients. Therefore, a simple modification-presence of brain stem signs is required for grade V-should be added to the WFNS classification. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT02304328.

Stenting and Angioplasty in Neurothrombectomy: Matched Analysis of Rescue Intracranial Stenting Versus Failed Thrombectomy.

BACKGROUND: Successful reperfusion is one of the strongest predictors of functional outcomes after mechanical thrombectomy (MT). Despite continuous advancements in MT technology and techniques, reperfusion failure still occurs in ≈15% to 30% of patients with large vessel occlusion strokes undergoing MT. We aim to evaluate the safety and efficacy of rescue intracranial stenting for large vessel occlusion stroke after failed MT. METHODS: The SAINT (Stenting and Angioplasty in Neurothrombectomy) Study is a retrospective analysis of prospectively collected data from 14 comprehensive stroke centers through January 2015 to December 2020. Patients were included if they had anterior circulation large vessel occlusion stroke due to intracranial internal carotid artery and middle cerebral artery-M1/M2 segments and failed MT. The cohort was divided into 2 groups: rescue intracranial stenting and failed recanalization (modified Thrombolysis in Cerebral Ischemia score 0-1). Propensity score matching was used to balance the 2 groups. The primary outcome was the shift in the degree of disability as measured by the modified Rankin Scale at 90 days. Secondary outcomes included functional independence (90-day modified Rankin Scale score 0-2). Safety measures included symptomatic intracranial hemorrhage and 90-day mortality. RESULTS: A total of 499 patients were included in the analysis. Compared with the failed reperfusion group, rescue intracranial stenting had a favorable shift in the overall modified Rankin Scale score distribution (acOR, 2.31 [95% CI, 1.61-3.32]; P<0.001), higher rates of functional independence (35.1% versus 7%; adjusted odds ratio [aOR], 6.33 [95% CI, 3.14-12.76]; P<0.001), and lower mortality (28% versus 46.5%; aOR, 0.55 [95% CI, 0.31-0.96]; P=0.04) at 90 days. Rates of symptomatic intracerebral hemorrhage were comparable across both groups (7.1% versus 10.2%; aOR, 0.99 [95% CI, 0.42-2.34]; P=0.98). The matched cohort analysis demonstrated similar results. Specifically, rescue intracranial stenting (n=107) had a favorable shift in the overall modified Rankin Scale score distribution (acOR, 3.74 [95% CI, 2.16-6.57]; P<0.001), higher rates of functional independence (34.6% versus 6.5%; aOR, 10.91 [95% CI, 4.11-28.92]; P<0.001), and lower mortality (29.9% versus 43%; aOR, 0.49 [95% CI, 0.25-0.94]; P=0.03) at 90 days with similar rates of symptomatic intracerebral hemorrhage (7.5% versus 11.2%; aOR, 0.87 [95% CI, 0.31-2.42]; P=0.79) compared with patients who failed to reperfuse (n=107). There was no heterogeneity of treatment effect across the prespecified subgroups for improvement in functional outcomes. CONCLUSIONS: Acute intracranial stenting appears to be a safe and effective rescue strategy in patients with large vessel occlusion stroke who failed MT. Randomized multicenter trials are warranted.

Safety of Antithrombotic Resumption in Chronic Subdural Hematoma Patients with Middle Meningeal Artery Embolization: A Case Control Study.

OBJECTIVE: Chronic subdural hematoma (CSDH) is a serious problem with an incidence of 20.6/100,000/year in North America and is posited to grow as the population ages. Middle Meningeal Artery (MMA) embolization is an upcoming therapy for treatment of CSDH. Among patients with CSDH who undergo MMA embolization outcomes are no different in patients who resume the antithrombotic (AT) after MMA embolization as compared to patients who don't resume AT. METHODS: We did retrospective review of all cases of MMA embolization in the setting of CSDH done over 2.5 years in 2 centers. Comparison of cases in which AT was resumed vs controls with no AT was performed. A successful outcome was defined as reduction of at least 50% volume in CSDH. Univariate analysis regarding all outcome measures for baseline variables was performed using Fisher exact test or t-test. Multivariate logistic regression with controlling for age, surgical evacuation of the hematoma. RESULTS: There were a total of 56 MMA embolization cases, 33 of them had no AT started and 23 of them had AT resumption at a mean of 2.4 days. About 40% of patients had surgical evacuation done prior to MMA embolization. There was no significant difference in hematoma reduction or volume even after adjusting for surgical evacuation (OR 1.00 95%CI 0.60- 1.67). Patients who had AT resumption had more CAD (71%vs 21% p= 0.001) and Afib (58% vs 18% p=0.002) necessitating AT. CONCLUSION: AT therapy can be safely resumed in CSDH after MMA embolization as there is no significant difference in CSDH volume reduction and recurrence.

Incidence and Outcome of Aneurysmal Subarachnoid Hemorrhage: The Swiss Study on Subarachnoid Hemorrhage (Swiss SOS).

BACKGROUND AND PURPOSE: The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level. METHODS: All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry. Incidence rates were calculated based on time-matched population data. Admission parameters and outcomes at discharge and at 1 year were recorded. RESULTS: We recorded data of 1787 consecutive patients. The incidence of aneurysmal subarachnoid hemorrhage in Switzerland was 3.7 per 100 000 persons/y. The number of female patients was 1170 (65.5%). With a follow-up rate of 91.3% at 1 year, 1042 patients (58.8%) led an independent life according to the modified Rankin Scale (0-2). About 1 in 10 patients survived in a dependent state (modified Rankin Scale, 3-5; n=185; 10.4%). Case fatality was 20.1% (n=356) at discharge and 22.1% (n=391) after 1 year. CONCLUSIONS: The current incidence of aneurysmal subarachnoid hemorrhage in Switzerland is lower than expected and an indication of a global trend toward decreasing admissions for ruptured intracranial aneurysms. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03245866.

Surgical selection and outcomes among elderly patients with brain arteriovenous malformations.

OBJECTIVE: Studies of resection of brain arteriovenous malformations (AVMs) in the elderly population are scarce. This study examined factors influencing patient selection and surgical outcome among elderly patients. METHODS: Patients 65 years of age and older who underwent resection of an unruptured or ruptured brain AVM treated by two surgeons at two centers were identified. Patient demographic characteristics, AVM characteristics, clinical presentation, and outcomes measured using the modified Rankin Scale (mRS) were analyzed. For subgroup analyses, patients were dichotomized into two age groups (group 1, 65-69 years old; group 2, ≥ 70 years old). RESULTS: Overall, 112 patients were included in this study (group 1, n = 61; group 2, n = 51). Most of the patients presented with hemorrhage (71%), a small nidus (< 3 cm, 79%), and a low Spetzler-Martin (SM) grade (grade I or II, 63%) and were favorable surgical candidates according to the supplemented SM grade (supplemented SM grade < 7, 79%). A smaller AVM nidus was statistically significantly more likely to be present in patients with infratentorial AVMs (p = 0.006) and with a compact AVM nidus structure (p = 0.02). A larger AVM nidus was more likely to be treated with preoperative embolization (p < 0.001). Overall outcome was favorable (mRS scores 0-3) in 71% of the patients and was statistically independent from age group or AVM grading. Patients with ruptured AVMs at presentation had significantly better preoperative mRS scores (p < 0.001) and more favorable mRS scores at the last follow-up (p = 0.04) than patients with unruptured AVMs. CONCLUSIONS: Outcomes were favorable after AVM resection in both groups of patients. Elderly patients with brain AVMs treated microsurgically were notable for small nidus size, AVM rupture, and low SM grades. Microsurgical resection is an important treatment modality for elderly patients with AVMs, and supplemented SM grading is a useful tool for the selection of patients who are most likely to achieve good neurological outcomes after resection. ABBREVIATIONS: AVM = arteriovenous malformation; BNI = Barrow Neurological Institute; LY = Lawton-Young; mRS = modified Rankin Scale; SM = Spetzler-Martin; supp-SM = supplemented SM; UCSF = University of California, San Francisco.

Ambulatory neurosurgery in the COVID-19 era: patient and provider satisfaction with telemedicine.

OBJECTIVE: Telemedicine has rapidly expanded in the recent years as technologies have afforded healthcare practitioners the ability to diagnose and treat patients remotely. Due to the COVID-19 pandemic, nonessential clinical visits were greatly limited, and much of the outpatient neurosurgical practice at the authors' institution was shifted quickly to telehealth. Although there are prior data suggesting that the use of telemedicine is satisfactory in other surgical fields, data in neurosurgery are limited. This study aimed to investigate both patient and provider satisfaction with telemedicine and its strengths and limitations in outpatient neurosurgery visits. METHODS: This quality improvement study was designed to analyze provider and patient satisfaction with telemedicine consultations in an outpatient neurosurgery clinic setting at a tertiary care, large-volume, academic center. The authors designed an 11-question survey for neurosurgical providers and a 13-question survey for patients using both closed 5-point Likert scale responses and multiple choice responses. The questionnaires were administered to patients and providers during the period when the clinic restricted in-person visits. At the conclusion of the study, the overall data were analyzed qualitatively and quantitatively. RESULTS: During the study period, 607 surveys were sent out to patients seen by telehealth at the authors' academic center, and 122 responses were received. For the provider survey, 85 surveys were sent out to providers at the authors' center and other academic centers, and 40 surveys were received. Ninety-two percent of patients agreed or strongly agreed that they were satisfied with that particular telehealth visit. Eighty-eight percent of patients agreed that their telehealth visit was more convenient for them than an in-person visit, but only 36% of patients stated they would like their future visits to be telehealth. Sixty-three percent of providers agreed that telehealth visits were more convenient for them than in-person visits, and 85% of responding providers stated that they wished to incorporate telehealth into their future practice. CONCLUSIONS: Although the authors' transition to telehealth was both rapid and unexpected, most providers and patients reported positive experiences with their telemedicine visits and found telemedicine to be an effective form of ambulatory neurosurgical care. Not all patients preferred telemedicine visits over in-person visits, but the high satisfaction with telemedicine by both providers and patients is promising to the future expansion of telehealth in ambulatory neurosurgery.

Elective Sonolucent Cranioplasty for Real-Time Ultrasound Monitoring of Flow and Patency of an Extra- to Intracranial Bypass.

Cross-sectional imaging studies or catheter angiogram are the imaging modalities of choice to evaluate bypass patency after extra- to intracranial (EC-IC) bypass surgery. Although providing accurate results, these imaging modalities are time-consuming and/or present radiation risk for the patient. Ultrasound imaging is a fast and widely available imaging modality, but is limited in this setting due to the non-sonolucent autologous bone flap covering the bypass after surgery. The recently FDA approved clear polymethyl methacrylate (PMMA) cranioplasty implant overcomes this limitation by its sonolucent characteristic, but has not yet been used in the setting of EC-IC bypass surgery. Here, the authors describe for the first time the feasibility of an elective sonolucent cranioplasty to monitor flow and patency of an EC-IC bypass in real time using ultrasound. This moyamoya patient underwent a direct superficial temporal artery to middle cerebral artery (STA-MCA) bypass, after which a PMMA implant was used to close the craniotomy defect, instead of reimplanting the autologous bone flap. Immediate postoperative bedside transcranioplasty ultrasound confirmed bypass patency and allowed for quantitative flow measurements as well as for exclusion of postoperative hemorrhage. Postoperative CTA and catheter angiogram confirmed patency of the bypass without complications. This report shows for the first time that this technique is feasible and permits bedside transcranioplasty ultrasound assessment of bypass flow in real time, confirmed with angiography. This technique may permit easy comparison of baseline findings with follow up assessments and facilitate less invasive monitoring of bypass patency.

Recent Nationwide Impact of Mechanical Thrombectomy on Decompressive Hemicraniectomy for Acute Ischemic Stroke.

Background and Purpose- The treatment of patients with acute ischemic stroke has been revolutionized by endovascular mechanical thrombectomy (MT), leading to dramatically improved outcomes. Here, we analyzed the impact of recent changes in stroke management on nationwide trends in patient characteristics, treatment modalities, and outcomes. Methods- The National Inpatient Sample was analyzed using International Classification of Diseases, Ninth and Tenth Editions, Clinical Modification codes to identify adult stroke patients with anterior-circulation, large-vessel occlusion in the pre- (2012-2014) and the post-MT trial period (2015-2016). Univariate and multivariable predictors of decompressive hemicraniectomy (DHC) were ascertained in patients developing malignant cerebral edema. Results- The nationwide query identified 519 320 adult stroke patients with annually increasing volume (92 320 to 129 340), stroke severity, and treatment at urban teaching centers. DHC was performed in 9.5% of patients developing malignant cerebral edema (n=33 530) and was associated with a high rate of discharge to long-term nursing care (65%) and mortality (23%). Over time, the rate of MT (3.4% to 9.8%) increased whereas the rate of DHC for malignant cerebral edema declined from 11.4% to 4.8% (P<0.001). In a binary logistic regression model controlling for potential confounders (eg, age, severity of illness), MT patients were 43% less likely to require DHC (odds ratio, 0.7; 95% CI, 0.6-0.9). Conclusions- Nationwide trends indicated that successful reperfusion of penumbra with MT in stroke patients leads to a declining indication for DHC whereas stroke volume increases over time.

National trends in cerebral bypass surgery in the United States, 2002-2014.

OBJECTIVECerebral bypass procedures are microsurgical techniques to augment or restore cerebral blood flow when treating a number of brain vascular diseases including moyamoya disease, occlusive vascular disease, and cerebral aneurysms. With advances in endovascular therapy and evolving evidence-based guidelines, it has been suggested that cerebral bypass procedures are in a state of decline. Here, the authors characterize the national trends in cerebral bypass surgery in the United States from 2002 to 2014.METHODSUsing the National (Nationwide) Inpatient Sample, the authors extracted for analysis the data on all adult patients who had undergone cerebral bypass as indicated by ICD-9-CM procedure code 34.28. Indications for bypass procedures, patient demographics, healthcare costs, and regional variations are described. Results were stratified by indication for cerebral bypass including moyamoya disease, occlusive vascular disease, and cerebral aneurysms. Predictors of inpatient complications and death were evaluated using multivariable logistic regression analysis.RESULTSFrom 2002 to 2014, there was an increase in the annual number of cerebral bypass surgeries performed in the United States. This increase reflected a growth in the number of cerebral bypass procedures performed for adult moyamoya disease, whereas cases performed for occlusive vascular disease or cerebral aneurysms declined. Inpatient complication rates for cerebral bypass performed for moyamoya disease, vascular occlusive disease, and cerebral aneurysm were 13.2%, 25.1%, and 56.3%, respectively. Rates of iatrogenic stroke ranged from 3.8% to 20.4%, and mortality rates were 0.3%, 1.4%, and 7.8% for moyamoya disease, occlusive vascular disease, and cerebral aneurysms, respectively. Multivariate logistic regression confirmed that cerebral bypass for vascular occlusive disease or cerebral aneurysm is a statistically significant predictor of inpatient complications and death. Mean healthcare costs of cerebral bypass remained unchanged from 2002 to 20014 and varied with treatment indication: moyamoya disease $38,406 ± $483, vascular occlusive disease $46,618 ± $774, and aneurysm $111,753 ± $2381.CONCLUSIONSThe number of cerebral bypass surgeries performed for adult revascularization has increased in the United States from 2002 to 2014. Rising rates of surgical bypass reflect a greater proportion of surgeries performed for moyamoya disease, whereas bypasses performed for vascular occlusive disease and aneurysms are decreasing. Despite evolving indications, cerebral bypass remains an important surgical tool in the modern endovascular era and may be increasing in use. Stagnant complication rates highlight the need for continued interest in advancing available bypass techniques or technologies to improve patient outcomes.

Feasibility and safety of intraoperative BOLD functional MRI cerebrovascular reactivity to evaluate extracranial-to-intracranial bypass efficacy.

Blood oxygenation level-dependent functional MRI cerebrovascular reactivity (BOLD-CVR) is a contemporary technique to assess brain tissue hemodynamic changes after extracranial- intracranial (EC-IC) bypass flow augmentation surgery. The authors conducted a preliminary study to investigate the feasibility and safety of intraoperative 3-T MRI BOLD-CVR after EC-IC bypass flow augmentation surgery. Five consecutive patients selected for EC-IC bypass revascularization underwent an intraoperative BOLD-CVR examination to assess early hemodynamic changes after revascularization and to confirm the safety of this technique. All patients had a normal postoperative course, and none of the patients exhibited complications or radiological alterations related to prolonged anesthesia time. In addition to intraoperative flow measurements of the bypass graft, BOLD-CVR maps added information on the hemodynamic status and changes at the brain tissue level. Intraoperative BOLD-CVR is feasible and safe in patients undergoing EC-IC bypass revascularization. This technique can offer immediate hemodynamic feedback on brain tissue revascularization after bypass flow augmentation surgery.