Mechanical thrombectomy versus intravenous thrombolysis for distal large-vessel occlusion: a systematic review and meta-analysis of observational studies.

OBJECTIVE: While several studies have compared the feasibility and safety of mechanical thrombectomy (MT) for distal large-vessel occlusion (LVO) strokes in patients, few studies have compared MT with intravenous thrombolysis (IVT) alone. The purpose of this systematic review was to compare the effectiveness and safety between MT and standard medical management with IVT alone for patients with distal LVOs. METHODS: PubMed, Google Scholar, Embase, Scopus, Web of Science, Ovid Medline, and Cochrane Library were searched in order to identify studies that directly compared MT with IVT for distal LVOs (anterior cerebral artery A2, middle cerebral artery M3-4, and posterior cerebral artery P2-4). Primary outcomes of interest included a modified Rankin Scale (mRS) score of 0 to 2 at 90 days posttreatment, occurrence of symptomatic intracerebral hemorrhage (sICH), and all-cause mortality at 90 days posttreatment. RESULTS: Four studies representing a total of 381 patients were included in this meta-analysis. The pooled results indicated that the proportion of patients with an mRS score of 0 to 2 at 90 days (OR 1.16, 95% CI 0.23-5.93; p = 0.861), the occurrence of sICH (OR 2.45, 95% CI 0.75-8.03; p = 0.140), and the mortality rate at 90 days (OR 1.73, 95% CI 0.66-4.55; p = 0.263) did not differ between patients who underwent MT and those who received IVT alone. CONCLUSIONS: The meta-analysis did not demonstrate a significant difference between MT and standard medical management with regard to favorable outcome, occurrence of sICH, or 90-day mortality. Prospective clinical trials are needed to further compare the efficacy of MT with IVT alone for distal vessel occlusion.

Comparison of effectiveness and outcomes among different thrombectomy techniques in acute basilar artery occlusion: a dual-center experience.

OBJECTIVE: Acute basilar artery occlusion (BAO) is a rare large-vessel occlusion associated with high morbidity and mortality. Modern thrombectomy with stent retrievers and large-bore aspiration catheters is highly effective in achieving recanalization, but a direct comparison of different techniques for acute BAO has not been performed. Therefore, the authors sought to compare the technical effectiveness and clinical outcomes of stent retriever-assisted aspiration (SRA), aspiration alone (AA), and a stent retriever with or without manual aspiration (SR) for treatment of patients presenting with acute BAO and to evaluate predictors of clinical outcome in their cohort. METHODS: A retrospective analysis of databases of large-vessel occlusion treated with endovascular intervention at two US endovascular neurosurgery centers was conducted. Patients ≥ 18 years of age with acute BAO treated between January 2013 and December 2020 with stent retrievers or large-bore aspiration catheters were included in the study. Demographic information, procedural details, angiographic results, and clinical outcomes were extracted for analysis. RESULTS: Eighty-three patients (median age 67 years [IQR 58-76 years]) were included in the study; 33 patients (39.8%) were female. The median admission National Institutes of Health Stroke Scale (NIHSS) score was 16 (IQR 10-21). Intravenous alteplase was administered to 26 patients (31.3%). The median time from symptom onset to groin or wrist puncture was 256 minutes (IQR 157.5-363.0 minutes). Overall, successful recanalization was achieved in 74 patients (89.2%). The SRA technique had a significantly higher rate of modified first-pass effect (mFPE; 55% vs 31.8%, p = 0.032) but not true first-pass effect (FPE; 45% vs 34.9%, p = 0.346) than non-SRA techniques. Good outcome (modified Rankin Scale [mRS] score 0-2) was not significantly different among the three techniques. Poor outcome (mRS score 3-6) was associated with a higher median admission NIHSS score (12.5 vs 19, p = 0.007), a higher rate of adjunctive therapy usage (9% vs 0%, p < 0.001), and a higher rate of intraprocedural complications (10.7% vs 14.5%, p = 0.006). The admission NIHSS score significantly predicted good outcome (OR 0.98, 95% CI 0.97-0.099; p = 0.032). Incomplete recanalization after thrombectomy significantly predicted mortality (OR 1.68, 95% CI 1.18-2.39; p = 0.005). CONCLUSIONS: The evaluated techniques resulted in high recanalization rates. The SRA technique was associated with a higher rate of mFPE than AA and SR, but the clinical outcomes were similar. A lower admission NIHSS score predicted a better prognosis for patients, whereas incomplete recanalization after thrombectomy predicted mortality.

Is Endovascular Therapy for Stroke Cost-Effective Globally? A Systematic Review of the Literature.

OBJECTIVES: Cost-effectiveness of endovascular therapy (EVT) is a key consideration for broad use of this approach for emergent large vessel occlusion stroke. We evaluated the evidence on cost-effectiveness of EVT in comparison with best medical management from a global perspective. MATERIALS AND METHODS: This systematic review of studies published between January 2010 and May 2020 evaluated the cost effectiveness of EVT for patients with large vessel occlusion acute ischemic stroke. The gain in quality adjusted life year (QALY) and incremental cost-effectiveness ratio (ICER), expressed as cost per QALY resulting from EVT, were recorded. The study setting (country, economic perspective), decision model, and data sources used in economic models of EVT cost-effectiveness were recorded. RESULTS: Twenty-five original studies from 12 different countries were included in our review. Five of these studies were reported from a societal perspective; 18 were reported from a healthcare system perspective. Two studies used real-world data. The time horizon varied from 1 year to a lifetime; however, 18 studies reported a time horizon of >10 years. Twenty studies reported using outcome data from randomized, controlled clinical trials for their models. Nineteen studies reported using a Markov model. Incremental QALYs ranged from 0.09-3.5. All studies but 1 reported that EVT was cost-effective. CONCLUSIONS: Evidence from different countries and economic perspectives suggests that EVT for stroke treatment is cost-effective. Most cost-effectiveness studies are based on outcome data from randomized clinical trials. However, there is a need to study the cost-effectiveness of EVT based solely on real-world outcome data.

Efficacy and safety of gamma knife radiosurgery for posterior cranial fossa meningioma: a systematic review.

The management of posterior cranial fossa meningioma [PCFM] is challenging and many neurosurgeons advise gamma knife radiosurgery [GKRS] as a modality for its upfront or adjuvant treatment. Due to the varying radiosurgical response based on lesion location, tumor biology, and radiation dosage, we performed a pioneer attempt in doing a systematic review analyzing the treatment efficacy and safety profile of GKRS for PCFM based on current literature. A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses [PRISMA] guidelines. A thorough literature search was conducted on PubMed, Web of science, and Cochrane data base; articles were selected systematically based on PRISMA protocol, reviewed completely, and relevant data was summarized and discussed. A total of 18 publications pertaining to GKRS for PCFM were included with a pooled sample size of 2131 patients. The median pre-GKRS tumor volume ranged from 2.28 to 10.5 cm [3]. Primary GKRS was administered in 61.1% of the pooled study cohorts, adjuvant treatment in 32.9%, and salvage therapy in 6.5% patients. Majority of the meningiomas were WHO grade 1 tumors (99.7%). The pooled mean marginal dose in the studies was 13.6 Gy (range 12-15.2 Gy) while the mean of maximum doses was 28.6 Gy (range 25-35 Gy). Most studies report an excellent radiosurgical outcome including the tumor control rate and the progression-free survival [PFS] of over 90%. The tumor control, PFS, and adverse radiation effect [ARE] rates in author's series were 92.3%, 91%, and 9.6%, respectively. The favorable radiosurgical outcome depends on multiple factors such as small tumor volume, absence of previous radiotherapy, tumor location, elderly patients, female gender, longer time from symptom onset, and decreasing maximal dose. GKRS as primary or adjuvant treatment modality needs to be considered as a promising management strategy for PCFM in selected patients in view of the growing evidence of high tumor control rate, improved neurological functions, and low incidence of ARE. The use of multiple isocenters, 3-D image planning, and limit GKRS treatment to tumors less than 3.5 cm help to avoid complications and achieve the best results. The treatment decisions in PCFM cases must be tailored and should consider the factors such as radiological profile, symptom severity, performance level, and patient preference for a good outcome.

Sovereign immunity and its implications for neurosurgery.

The proportion of neurosurgeons facing a malpractice suit each year is highest among all medical and surgical specialties. It is critical for neurosurgeons to understand local malpractice laws because they vary among states. Sovereign immunity, as described in the 11th constitutional amendment, provides absolute immunity to states from being sued by their residents and by other states. A state may waive its sovereign immunity, however, and substitute itself as the defendant in place of a state-employed physician in the court of law. This means that a physician working for a state-funded hospital may not be liable to a malpractice suit. Further provisions of the law allow the state not to pay indemnity beyond a certain limit, which discourages plaintiff attorneys from pursuing indemnity charges against physicians working for state-funded institutions. In this review, the authors describe the concept of sovereign immunity and its implications for the practice of neurosurgery.

Efficacy and safety of middle meningeal artery embolization in the management of refractory or chronic subdural hematomas: a systematic review and meta-analysis.

INTRODUCTION: Refractory or chronic subdural hematomas (cSDH) constitute a challenging entity that neurosurgeons face frequently nowadays. Middle meningeal artery embolization (MMAE) has emerged in the recent years as a promising treatment option. However, solid evidence that can dictate management guidelines is still lacking. METHODS: We conducted a systematic review and meta-analysis (MA) in compliance with the PRISMA guidelines to evaluate the efficacy and safety of MMAE compared with conventional treatments for refractory or cSDH. Databases were searched up to March 2019. Using a random-effects model, meta-analyses of proportions and risk difference were conducted recurrence, need for surgical rescue, and complications. RESULTS: Eleven studies (177 patients) were included. Majority (116, 69%) were males with a weighted mean age of 71 + -19.5 years. Meta-analysis of proportions showed treatment failure to be 2.8%, need for surgical rescue 2.7%, and embolization-related complications 1.2%. Meta-analysis of risk-difference between embolized and non-embolized patients showed a 26% (p < 0.001, 95% CI 21%-31%, I2 = 0) lower risk of hematoma recurrence in MMAE. Similarly, in the embolized group, the need for surgical rescue was 20% less (p < 0.001, 95% CI = 12%-27%, I2 = 12.4), and complications were 3.6% less (p = 0.008, 95% CI 1%-6%, I2 = 0) compared to conventional groups. CONCLUSIONS: Although MMAE appears to be a promising treatment for refractory or cSDH, drawing definitive conclusions remains limited by paucity of data and small sample sizes. Multicenter, randomized, prospective trials are needed to compare embolization to conventional treatments like watchful waiting, medical management, or surgical evacuation. More extensive research on MMAE could begin a new era in the minimally invasive management of cSDH.

Size of ruptured intracranial aneurysms: a systematic review and meta-analysis.

BACKGROUND: There is wide variation in the reported size of ruptured intracranial aneurysms and methods of size estimation. There is widespread belief that small aneurysms < 7 mm do not rupture. Therefore, we performed a systematic review and meta-analysis of the literature to determine the size of ruptured aneurysms according to aneurysm locations and methods of size estimation. METHODS: We searched PubMed, Cochrane, CINAHL, and EMBASE databases using a combination of Medical Subject Headings (MeSH) terms. We included articles that reported mean aneurysm size in consecutive series of ruptured intracranial. We excluded studies limited to a specific aneurysm location or type. The random-effects model was used to calculate overall mean size and location-specific mean size. We performed meta-regression to explain observed heterogeneity and variation in reported size. RESULTS: The systematic review included 36 studies and 12,609 ruptured intracranial aneurysms. Overall mean aneurysm size was 7.0 mm (95% confidence interval [CI 6.2-7.4]). Pooled mean size varied with location. Overall mean size of 2145 ruptured anterior circulation aneurysms was 6.0 mm (95% CI 5.6-6.4, residual I2 = 86%). Overall mean size of 743 ruptured posterior circulation aneurysms was 6.2 mm (95% CI 5.3-7.0, residual I2 = 93%). Meta-regression identified aneurysm location and definition of size (i.e., maximum dimension vs. aneurysm height) as significant determinants of aneurysm size reported in the studies. CONCLUSIONS: The mean size of ruptured aneurysms in most studies was approximately 7 mm. The general wisdom that aneurysms of this size do not rupture is incorrect. Location and size definition were significant determinants of aneurysm size.

Impact of endovascular reperfusion on low National Institutes of Health Stroke Scale score large-vessel occlusion stroke.

INTRODUCTION: Effectiveness of mechanical thrombectomy for mild-deficit stroke due to large-vessel occlusion is controversial. We present a single-center consecutive case series on thrombectomy for large-vessel occlusion mild stroke. We evaluated various thrombectomy parameters to better understand disagreement in the literature. METHODS: Data from a retrospective cohort of large-vessel occlusion mild stroke patients (National Institutes of Health Stroke Scale <6) treated with mechanical thrombectomy over 6 years and 2 months were analyzed. Patients were divided into 2 groups: successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b or 3) and failed reperfusion (modified Thrombolysis in Cerebral Infarction 0,1, or 2a). Ninety-day modified Rankin Scale in-hospital mortality, and symptomatic hemorrhage rates were compared between groups. Multivariate logistic regression was performed to evaluate reperfusion status as a predictor of 90-day favorable (modified Rankin Scale 0-2) and excellent (modified Rankin Scale 0-1) outcomes. RESULTS: We identified 61 patients with large-vessel occlusion mild stroke who underwent thrombectomy. Reperfusion was successful in 49 patients and a failure in 12. The successful group exhibited significantly higher rates of favorable outcome (83.7% vs. 25.0%; p < 0.001) and excellent outcome (69.4% vs.16.7%; p = 0.002) at 90 days. In-hospital mortality was significantly higher in the failure group (41.7% vs.10.2%; p = 0.019). Multivariate logistic regression identified successful reperfusion as a significant predictor (p = 0.001) of 90-day favorable outcome. CONCLUSION: Reperfusion success was significantly associated with improved functional outcomes in large-vessel occlusion mild stroke mechanical thrombectomy. Future studies should consider reperfusion rates when evaluating the effectiveness of thrombectomy against that of medical management in these patients.

Jacques Jean Lhermitte and the syndrome of peduncular hallucinosis.

Jacques Jean Lhermitte (1877-1959) was among the most accomplished neurologists of the 20th century. In addition to working as a clinician and instructor, he authored more than 800 papers and 16 books on neurology, neuropathology, psychiatry, and mystical phenomena. In addition to the well-known "Lhermitte's sign," an electrical shock-like sensation caused by spinal cord irritation in demyelinating disease, Lhermitte was a pioneer in the study of the relationship between the physical substance of the brain and the experience of the mind. A fascinating example of this is the syndrome of peduncular hallucinosis, characterized by vivid visual hallucinations occurring in fully lucid patients. This syndrome, which was initially described as the result of a midbrain insult, also may occur with injury to the thalamus or pons. It has been reported as a presenting symptom of various tumors and as a complication of neurosurgical procedures. Here, the authors review the life of Lhermitte and provide a historical review of the syndrome of peduncular hallucinosis.

A comparison of the techniques of direct pars interarticularis repairs for spondylolysis and low-grade spondylolisthesis: a meta-analysis.

OBJECTIVE Spondylosis with or without spondylolisthesis that does not respond to conservative management has an excellent outcome with direct pars interarticularis repair. Direct repair preserves the segmental spinal motion. A number of operative techniques for direct repair are practiced; however, the procedure of choice is not clearly defined. The present study aims to clarify the advantages and disadvantages of the different operative techniques and their outcomes. METHODS A meta-analysis was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The following databases were searched: PubMed, Cochrane Library, Web of Science, and CINAHL ( Cumulative Index to Nursing and Allied Health Literature). Studies of patients with spondylolysis with or without low-grade spondylolisthesis who underwent direct repair were included. The patients were divided into 4 groups based on the operative technique used: the Buck repair group, Scott repair group, Morscher repair group, and pedicle screw-based repair group. The pooled data were analyzed using the DerSimonian and Laird random-effects model. Tests for bias and heterogeneity were performed. The I2 statistic was calculated, and the results were analyzed. Statistical analysis was performed using StatsDirect version 2. RESULTS Forty-six studies consisting of 900 patients were included in the study. The majority of the patients were in their 2nd decade of life. The Buck group included 19 studies with 305 patients; the Scott group had 8 studies with 162 patients. The Morscher method included 5 studies with 193 patients, and the pedicle group included 14 studies with 240 patients. The overall pooled fusion, complication, and outcome rates were calculated. The pooled rates for fusion for the Buck, Scott, Morscher, and pedicle screw groups were 83.53%, 81.57%, 77.72%, and 90.21%, respectively. The pooled complication rates for the Buck, Scott, Morscher, and pedicle screw groups were 13.41%, 22.35%, 27.42%, and 12.8%, respectively, and the pooled positive outcome rates for the Buck, Scott, Morscher, and pedicle screw groups were 84.33%, 82.49%, 80.30%, and 80.1%, respectively. The pedicle group had the best fusion rate and lowest complication rate. CONCLUSIONS The pedicle screw-based direct pars repair for spondylolysis and low-grade spondylolisthesis is the best choice of procedure, with the highest fusion and lowest complication rates, followed by the Buck repair. The Morscher and Scott repairs were associated with a high rate of complication and lower rates of fusion.

Endovascular Retrieval of Migrated Distal End of Ventriculoperitoneal Shunt from Bilateral Pulmonary Arteries: A Technical Note.

Ventriculoperitoneal (VP) shunting of cerebrospinal fluid is one of the most common procedures performed by neurosurgeons around the world. Migration of distal VP shunt catheter into bilateral segmental pulmonary arteries is an extremely rare complication of VP shunt placement. In the present case, a 30-year-old male underwent VP shunting complicated by migration of distal VP shunt catheter into the bilateral pulmonary arteries. Despite manual attempt at externalizing the distal VP shunt catheter at the level of the clavicle, a small piece of distal VP shunt catheter in bilateral pulmonary arteries was noted on computed tomography of the chest obtained after manual externalization. This persistent distal VP shunt catheter was likely left behind after a break in the distal VP shunt catheter during manual externalization procedure. Given the small size of the segmental pulmonary arteries, a novel endovascular technique was used to move the distal VP shunt catheter from the bilateral segmental pulmonary arteries to the main pulmonary trunk. Once in the main pulmonary trunk, a snare device was used to retrieve the distal shunt catheter through the femoral vein. In this technical note, the authors highlight the relevant endovascular technical details to first move the VP shunt catheter from the bilateral segmental arteries followed by successful catheter retrieval using snare device.

An Anatomic Assessment of the Intercavernous Sinuses and Review of the Literature.

Introduction As expanded endoscopic endonasal approaches are gaining popularity, a thorough understanding of the anatomy of the intercavernous sinuses is pertinent to avoid bleeding complications. There have been few studies reporting the presence and dimensions of the anterior intercavernous sinus (AIS), posterior intercavernous sinus (PIS), and inferior intercavernous sinus (IIS). We performed a cadaveric study to better understand these structures. Methods Colored latex was injected into the arterial and venous trees of 17 cadaveric heads. Dissections assessed the presence and dimensions of the AIS, PIS, and IIS. In an additional three specimens, the sellar contents were subjected to histological analysis. Results Of the 20 total specimens, 13 (65%) demonstrated the gross presence of all three sinuses. In six specimens (30%), only the AIS and PIS could be identified, and in one specimen, only an AIS and IIS were identified. An AIS was identified in all 20 (100%) specimens, PIS in 18 (88%), and an IIS in 14 (70%). In two specimens (10%), the AIS covered the entire face of the sella. Dimensions of the AIS averaged 1.7 × 11.7 × 2.8 mm, PIS averaged 1.5 × 10.8 × 1.7 mm, and IIS averaged 8.7 × 11.8 × 1.0 mm when present. Conclusion All examined specimens demonstrated the presence of an AIS, and most had a PIS. The presence of an IIS was more variable. Preoperative awareness of these sinuses is helpful in planning transsphenoidal surgery to minimize the risk of bleeding.

Rist Guide Catheter for Endovascular Procedures: Initial Case Series from a Single Center.

BACKGROUND: The transradial approach (TRA) for endovascular procedures has become a frequent practice in neurointervention. Advantages of the TRA include less access-site complications, early ambulation, and less postprocedural pain. The Rist 079 radial access guide catheter (Medtronic) is the first device designed specifically for neurointerventions performed through the TRA. In this study, we report our initial experience with the Rist catheter in a variety of neurointerventional procedures, aiming to evaluate the performance of this device and discuss its limitations. METHODS: A prospectively maintained database was retrospectively searched to identify patients who underwent procedures using the Rist catheter. Information on demographics, procedural details, and complications was recorded. RESULTS: Seventy-eight patients were included in the study, with a mean age of 60.3 years (range, 25-92 years); 45 (57.7%) were men. The interventional or diagnostic procedure was successfully completed in 77 patients (98.7%). The radial artery was the primary access-site choice in 71 patients (91%). The most frequent type of procedures performed were coiling or stent-assisted coiling (16.7%) and angioplasty and stenting (16.7%), followed by middle meningeal artery embolization (14.1%). Crossover to femoral artery access while maintaining use of the Rist was done in 5 cases (6.4%). Reasons for access or procedural failure included anatomical anomaly of the target vessel, unfavorable geometry of the great vessels, and proximal tortuosity of the supra-aortic vessels. CONCLUSION: We demonstrated a high success rate with use of the Rist catheter system for a variety of procedures.

Acute isolated posterior cerebral artery stroke treated with mechanical thrombectomy: A single-center experience and review of the literature.

BACKGROUND: Acute isolated posterior cerebral artery (PCA) occlusions account for 5-10% of all ischemic events. Due to peculiar patient presentation, the potential benefit of mechanical thrombectomy (MT) remains controversial. We evaluated the safety, feasibility, and effectiveness of MT in our patients and compared our results with the literature review conducted. METHODS: Charts were reviewed retrospectively for consecutive patients diagnosed with acute PCA stroke who underwent MT. Demographics, procedural, and follow-up details were noted. For the literature review, a systematic search of PubMed, MEDLINE, and EMBASE databases was conducted for the keywords "posterior cerebral artery" and "thrombectomy" for articles published between January 1, 2010 and June 30, 2021. Estimated rates for recanalization, favorable outcomes (modified Rankin Scale [mRS] score 0-2), symptomatic intracerebral hemorrhage (sICH), and mortality were extracted. RESULTS: Our cohort included 21 patients. Mean age was 71.2 years (standard deviation [SD] ± 10.2). Median National Institutes of Health Stroke Scale (NIHSS) presentation score was 9 (interquartile range [IQR] 5-15), with visual symptoms reported in 12(57.1%) patients. Overall, final modified thrombolysis in cerebral infarction (mTICI) 2b-3 was achieved in 17 patients (80.9%) with first-pass mTICI 2b-3 attained in 8 (38.1%). Postprocedure sICH occurred in 1 (4.8%) patient. Fifteen (71.4%) patients had a 0-2 mRS score at 90 days. Visual symptoms resolved in 10 of 12(83.3%) patients. Mortality occurred in 2 (9.5%) patients. For the systematic review, cohorts from 4 articles plus ours were included, totaling 222 patients. The estimated rate of successful recanalization was 85.25% (95% confidence interval[CI], 73.05%-97.45%), sICH was 3.60% (95% CI, 1.11%-6.09%), and mortality was 10.51% (95% CI, 5.88%-15.15%). CONCLUSION: The results of our series and systematic review indicate MT as a potentially safe and effective treatment modality for acute PCA stroke. These results also indicate that patient selection and assessment may be the key in obtaining favorable outcomes.

The impact of brain atrophy on the outcomes of mechanical thrombectomy.

OBJECTIVE: Pre-existing brain atrophy may affect the outcomes of patients treated with mechanical thrombectomy (MT) for large-vessel-occlusion because it is an indicator of low brain reserve. We performed a systematic literature review to assess the impact of brain atrophy on MT-related clinical outcomes. METHODS: We conducted a systematic search of PubMed, MEDLINE, EMBASE, and Cochrane Library databases from inception to March 2021 using keywords with Boolean operators("brain atrophy"; "atrophy"; "white matter"; and "thrombectomy"). Articles published in English that evaluated the impact of pre-existing brain atrophy on outcomes of MT-treated acute ischemic stroke were eligible for inclusion. RESULTS: Four articles were included. Brain atrophy index was a predictor of mortality (odds ratio [OR]:1.81-1.87, 95% confidence interval [CI]:1.16-2.93) after adjustments for age and white matter lesions. Global cortical atrophy scale was an independent predictor of futile recanalization (OR 1.15, 95% CI 1.08-1.22) in multivariate-adjusted logistic regression. Automated measurement of CSF identified increasing volumes associated with reduced 3-month functional independence and higher modified Rankin scale scores. STandards for ReportIng Vascular changes on Neuroimaging criteria for brain atrophy were associated with unfavorable outcome in ordinal-shift analysis (OR 2.72, 95% CI 1.25-5.91). CONCLUSIONS: The few studies available highlight heterogeneity of neuroimaging methodologies for assessing brain atrophy and difficulty addressing the multiple confounders involved in clinical outcomes. More consistent, accurate investigation is needed before proposing brain atrophy as a possible parameter to improve patient selection for MT. ADVANCES IN KNOWLEDGE: Brain atrophy is associated with many of the clinical confounders frequently present in patients with acute ischemic stroke. Heterogeneity in classification methodologies for brain atrophy and complexity analyzing multiple clinical confounders make it difficult to assess the true impact of this radiological finding on MT-related outcomes.

Use of Walrus balloon-guide catheter through sheathless radial approach for mechanical thrombectomy of right middle cerebral artery occlusion.

The literature demonstrates a favorable first pass effect with balloon-guide catheter (BGC) for mechanical thrombectomy. An 8F BGC is routinely used with femoral access. We present the first video report of 8F BGC advanced through the radial artery using a sheathless technique (video 1). An approximately 70-year-old patient presented with left-sided hemiplegia, neglect, and dysarthria. A CT angiogram demonstrated right M1 occlusion, and the patient underwent urgent mechanical thrombectomy. Radial approach was preferred owing to patient history of anticoagulation. A 6F Sim Select intermediate catheter was used to minimize the step off as the 8F BGC was advanced into the radial artery over an 035 exchange-length Advantage Glidewire. A skin nick over the Glidewire Advantage facilitated the introduction of the 8F BGC into the radial artery. Standard mechanical thrombectomy using a combination of stent retriever and aspiration catheter (Solumbra technique) was performed, and thrombolysis in cerebral infarction 3 recanalization was achieved after a single pass. The National Institutes of Health Scale score improved from 12 to 4, with mild left facial droop, dysarthria, and decreased speech fluency. The patient was discharged from the hospital on postoperative day 2. Ultrasound should be used for immediate assessment of radial artery size and conversion to femoral access without delay if the radial artery is less than 2.5 mm. neurintsurg;14/5/neurintsurg-2021-017985/V1F1V1Video 1.

Use of N-butyl 2-cyanoacrylate (nBCA) for preoperative tumor embolization.

N-butyl 2-cyanoacrylate (nBCA) is a fast-acting liquid adhesive that polymerizes when it comes in contact with blood anions. We present the principles of nBCA preparation and delivery for tumor embolization of a right convexity meningioma in a patient who presented with a 6-month history of word-finding difficulty and memory loss video 1 Angiography of the middle meningeal artery showed a hairpin turn that was not negotiable with a number of different microwires, including the Synchro-2, Chikai 014 and Balt hybrid 008 wire. Due to the tortuous hairpin turn, the microcatheter position was distal to the tumor blush for the convexity meningioma. Given the distal microcatheter position, we opted for nBCA as the liquid embolic of choice for tumor embolization. The time of polymerization for nBCA may be delayed using glacial acetic acid, which makes nBCA ideal when the microcatheter is in a distal position relative to the target location for embolization. The patient underwent successful embolization using nBCA and was taken for a right frontal craniotomy for resection of the meningioma the next day. The intraoperative blood loss was 100 mL and the postoperative MRI showed gross total resection. The patient had an uncomplicated hospital course and was discharged home on post-procedure day 3. neurintsurg;14/1/neurintsurg-2021-017400/V1F1V1Video 1.

Learning curves for transradial access versus transfemoral access in diagnostic cerebral angiography: a case series.

BACKGROUND: The perception of a steep learning curve associated with transradial access has resulted in its limited adoption in neurointervention despite the demonstrated benefits, including decreased access-site complications. OBJECTIVE: To compare learning curves of transradial versus transfemoral diagnostic cerebral angiograms obtained by five neurovascular fellows as primary operator. METHODS: The first 100-150 consecutive transradial and transfemoral angiographic scans performed by each fellow between July 2017 and March 2020 were identified. Mean fluoroscopy time per artery injected (angiographic efficiency) was calculated as a marker of technical proficiency and compared for every 25 consecutive procedures performed (eg, 1-25, 26-50, 51-75). RESULTS: We identified 1242 diagnostic angiograms, 607 transradial and 635 transfemoral. The radial cohort was older (64.3 years vs 62.3 years, p=0.01) and demonstrated better angiographic efficiency (3.4 min/vessel vs 3.7 min/vessel, p=0.03). For three fellows without previous endovascular experience, proficiency was obtained between 25 and 50 transfemoral angiograms. One fellow achieved proficiency after performing 25-50 transradial angiograms; and the two other fellows, in <25 transradial angiograms. The two fellows with previous experience had flattened learning curves for both access types. Two patients experienced transient neurologic symptoms postprocedure. Transradial angiograms were associated with significantly fewer access-site complications (3/607, 0.5% vs 22/635, 3.5%, p<0.01). Radial-to-femoral conversion occurred in 1.2% (7/607); femoral-to-radial conversion occurred in 0.3% (2/635). Over time, the proportion of transradial angiographic procedures increased. CONCLUSION: Technical proficiency improved significantly over time for both access types, typically requiring between 25 and 50 diagnostic angiograms to achieve asymptomatic improvement in efficiency. Reduced access-site complications and decreased fluoroscopy time were benefits associated with transradial angiography.

Treatment of ruptured intracranial aneurysms with the Woven EndoBridge device: a systematic review.

The Woven EndoBridge (WEB) device is a barrel-shaped nitinol mesh deployed within the aneurysmal sac. The absence of metallic mesh in the aneurysm's parent vessel lumen obviates the need for potent antiplatelet therapy, making this device appealing for acutely ruptured aneurysms not amenable to clipping or coiling. To assess the literature regarding WEB treatment of these aneurysms, we performed a comprehensive systematic search of PubMed, MEDLINE, and EMBASE databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Keywords were combined with Boolean operators to increase search sensitivity and specificity ('woven endobridge device' AND 'ruptured'). Nine studies comprising 377 acutely ruptured aneurysms were included. Overall, 82.7% were wide-necked, 85.9% were located in the anterior circulation, and 26.9% of patients presented with poor subarachnoid hemorrhage grade. Intraprocedure and postprocedure complications occurred in 8.4% (95% CI 3.6% to 13.3%) and 1% (95% CI 0% to 2%), respectively. The post-treatment rebleeding rate was 0%. Rates of adequate occlusion (complete occlusion to neck remnant) and retreatment at last follow-up were 84.8% (95% CI 73% to 96.6%) and 4.5% (95% CI 2.2% to 6.8%), respectively. The favorable outcome rate (modified Rankin Scale score 0-2) was 62.2% (95% CI 53% to 71.4%); mortality was 13.6% (95% CI 9.7% to 17.6%). WEB treatment of acutely ruptured aneurysms results in high adequate occlusion rates, low perioperative complication rates, no rebleeding, and low recurrence requiring retreatment. This device is promising for acutely ruptured aneurysms not amenable to clipping or coiling, considering the lower need for antiplatelet regimens during the procedure or follow-up.