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OBJECTIVE Machine learning algorithms have shown groundbreaking results in neuroimaging. The authors herein evaluated the performance of a newly developed convolutional neural network (CNN) to detect and analyze intracranial aneurysms (IAs) on CTA. METHODS Consecutive patients with CTA studies between January 2015 and July 2021 at a single center were identified. The ground truth determination of cerebral aneurysm presence or absence was made from the neuroradiology report. The primary outcome was the performance of the CNN in detecting IAs in an external validation set, measured using area under the receiver operating characteristic curve statistics. Secondary outcomes included accuracy for location and size measurement. RESULTS The independent validation imaging data set consisted of 400 patients with CTA studies, median age 40 years (IQR 34 years) and 141 (35.3%) of whom were male; 193 patients (48.3%) had a diagnosis of IA on neuroradiologist evaluation. The median maximum IA diameter was 3.7 mm (IQR 2.5 mm). In the independent validation imaging data set, the CNN performed well with 93.8% sensitivity (95% CI 0.87–0.98), 94.2% specificity (95% CI 0.90–0.97), and a positive predictive value of 88.2% (95% CI 0.80–0.94) in the subgroup with an IA diameter ≥ 4 mm. CONCLUSIONS The described Viz.ai Aneurysm CNN performed well in identifying the presence or absence of IAs in an independent validation imaging set. Further studies are necessary to investigate the impact of the software on detection rates in a real-world setting.

Dural arteriovenous fistulas (dAVFs) located at craniocervical junction are extremely rare (1%-2% of intracranial/spinal dAVFs). Their angio-architectural complexity renders endovascular embolization to be challenging given multiple small feeders with risk of embolysate reflux into vertebral artery and limited transvenous access. The available literature discussing microsurgery for these lesions is limited to few case reports.To report a multicenter experience assessing microsurgery safety/efficacy.Prospectively maintained registries at 13 North American centers were queried to identify craniocervical junction dAVFs treated with microsurgery (2006-2021).Thirty-eight patients (median age 59.5 years, 44.7% female patients) were included. The most common presentation was subarachnoid/intracranial hemorrhage (47.4%) and myelopathy (36.8%) (92.1% of lesions Cognard type III-V). Direct meningeal branches from V3/4 vertebral artery segments supplied 84.2% of lesions. All lesions failed (n = 5, 13.2%) or were deemed inaccessible/unsafe to endovascular treatment. Far lateral craniotomy was the most used approach (94.7%). Intraoperative angiogram was performed in 39.5% of the cases, with angiographic cure in 94.7% of cases (median imaging follow-up of 9.2 months) and retreatment rate of 5.3%. Favorable last follow-up modified Rankin Scale of 0 to 2 was recorded in 81.6% of the patients with procedural complications of 2.6%.Craniocervical dAVFs represent rare entity of lesions presenting most commonly with hemorrhage or myelopathy because of venous congestion. Microsurgery using a far lateral approach provides robust exposure and visualization for these lesions and allows obliteration of the arterialized draining vein intradurally as close as possible to the fistula point. This approach was associated with a high rate of angiographic cure and favorable clinical outcomes.

The Pipeline Embolization Device (PED) has been the only flow-diverting device (FDD) approved by the Food and Drug Administration (FDA) in the U.S. market for nearly a decade, with more FDD choices in the United States following recent FDA approval of the Flow Redirection Endoluminal Device and Surpass. We sought to explore the integration patterns of these devices into practice by U.S. neurointerventionalists.A 34-question electronic survey was distributed to the U.S. neurointerventional community from different backgrounds (neurosurgery, neurology, radiology) through different organizational links, focusing on technical aspects of device selection and personal preferences/experiences regarding FDD in aneurysms treatment.Responses were collected from 120 neurointerventionalists across the United States; operators from a neurosurgery background constituted the majority of respondents (47.5%; 85% of dual-trained). The largest age block was early-to mid-career operators (70.8% aged 36-50 years). Most participants (78.8%) treated a range of 25-100 aneurysms/year with FDDs, with 49.2% of respondents having all the FDA-approved FDDs available in their centers (80.8% academic practice). Femoral access was used by the 67.7% of respondents, without impact of FDD-device on access-type (89.2%). PED was the most commonly used device (70.9%), with 66.7% of respondents reporting using different FDD based on case specifics. Comparing devices preferences by training backgrounds, more neurosurgical operators endorsed PED as their most commonly used device, whereas more interventional neuroradiologists/neurologists reported Surpass and Flow Redirection Endoluminal Device as their most commonly used devices.The results of this survey identify common themes in FDD choices among neurointerventionalists in the U.S. market, along with their integration patterns of the newly introduced devices into clinical practice.

Yong Fang Zhu,1,2 Peter Kan,3 Gurmit Singh1,2 1Michael G. DeGroote Institute for Pain Research and Care, McMaster University, Hamilton, ON, Canada; 2Department of Pathology & Molecular Medicine, McMaster University, Hamilton, ON, Canada; 3Health Sciences, McMaster University, Hamilton, ON, CanadaCorrespondence: Gurmit Singh, Email Singhg@mcmaster.caBackground: Clinical data on cancer-induced pain (CIP) demonstrate widespread changes in sensory function. It is characterized in humans not only by stimulus-invoked pain, but also by spontaneous pain. In our previous studies in an animal model of CIP, we observed changes in intrinsic membrane properties and excitability of dorsal root ganglion (DRG) sensory neurons corresponding to mechanical allodynia and hyperalgesia, of which abnormal activities of Aβ-fiber sensory neurons are consistent in a rat model of peripheral neuropathic pain (NEP).Objective: To investigate whether there are related peripheral neural mechanisms between the CIP and NEP models of spontaneous pain, we compared the electrophysiological properties of DRG sensory neurons at 2– 3 weeks after CIP and NEP model induction.Methods: CIP models were induced with metastasis tumour-1 rat breast cancer cells implanted into the distal epiphysis of the femur. NEP models were induced with a polyethylene cuff implanted around the sciatic nerve. Spontaneous pain in animals is measured by spontaneous foot lifting (SFL). After measurement of SFL, the animals were prepared for electrophysiological recordings of spontaneous activity (SA) in DRG neurons in vivo.Results: Our data showed that SFL and SA occurred in both models. The proportion of SFL and SA of C-fiber sensory neurons in CIP was more significantly increased than in NEP models. There was no difference in duration of SFL and the rate of SA between the two models. The duration of SFL is related to the rate of SA in C-fiber in both models.Conclusion: Thus, SFL may result from SA activity in C-fiber neurons in CIP and NEP rats. The differences and similarities in spontaneous pain between CIP and NEP rats is related to the proportion and rate of SA in C-fibers, respectively.Keywords: electrophysiology recording, spontaneous pain, sensory neuron, cancer-induced pain, neuropathic pain

OBJECTIVE Burnout and work-life balance have been noted to be problems for residents across all fields of medicine, including neurosurgery. No studies to date have evaluated how these factors may contribute to issues outside of the hospital, specifically residents’ home lives. This study aimed to evaluate the interplay between home life and work life of neurosurgical residents, specifically from the point of view of residents’ significant others. METHODS Online surveys were distributed to the significant others of neurosurgical residents at 12 US neurosurgery residencies. Residents’ partners were asked about relationship dynamics, their views on neurosurgery residency (work-life balance and burnout), and their views of neurosurgery as a career. RESULTS The majority of residents’ significant others (84%) reported being satisfied with their relationship. Significant others who reported dissatisfaction with their relationship were more likely to report frustration with work-life balance and more likely to report their resident partner as having higher levels of burnout. CONCLUSIONS From the perspective of neurosurgery residents’ significant others, higher perceived levels of burnout and lower satisfaction with work-life balance are correlated with lower levels of relationship satisfaction. These findings speak to the complex interplay of work life and home life and can be used to inform future interventions into improving the quality of life for both the resident and the significant other.

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 P 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 P 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.

Background The Woven EndoBridge (WEB) device was explicitly designed for wide-neck intracranial bifurcation aneurysms. Small-scale reports have evaluated the off-label use of WEB devices for the treatment of sidewall aneurysms, with promising outcomes. Purpose To compare the angiographic and clinical outcomes of the WEB device for the treatment of sidewall aneurysms compared with the treatment of bifurcation aneurysms. Materials and Methods A retrospective review of the WorldWideWEB Consortium, a synthesis of retrospective databases spanning from January 2011 to June 2021 at 22 academic institutions in North America, South America, and Europe, was performed to identify patients with intracranial aneurysms treated with the WEB device. Characteristics and outcomes were compared between bifurcation and sidewall aneurysms. Propensity score matching (PSM) was used to match by age, pretreatment ordinal modified Rankin Scale score, ruptured aneurysms, location of aneurysm, multiple aneurysms, prior treatment, neck, height, dome width, daughter sac, and incorporated branch. Results A total of 683 intracranial aneurysms were treated using the WEB device in 671 patients (median age, 61 years [IQR, 53-68 years]; male-to-female ratio, 1:2.5). Of those, 572 were bifurcation aneurysms and 111 were sidewall aneurysms. PSM was performed, resulting in 91 bifurcation and sidewall aneurysms pairs. No significant difference was observed in occlusion status at last follow-up, deployment success, or complication rates between the two groups. Conclusion No significantly different outcomes were observed following the off-label use of the Woven EndoBridge, or WEB, device for treatment of sidewall aneurysms compared with bifurcation aneurysms. The correct characterization of the sidewall aneurysm location, neck angle, and size is crucial for successful treatment and lower retreatment rate. © RSNA, 2022 See also the editorial by Hetts in this issue.

Middle meningeal artery embolization (MMAE) is an effective minimally invasive treatment for chronic subdural hematomas (cSDHs). The authors investigated outcomes of primary, adjunct, and rescue MMAE and primary surgery for the treatment of cSDH using a large-scale national database.A retrospective study of all patients who underwent MMAE and/or surgery to treat cSDH was performed using the TriNetX Analytics Network. Primary MMAE was compared with adjunct and rescue MMAE and primary surgery. Primary outcomes included headache, facial weakness, mortality, and treatment failure, within 6 months.A total of 4274 patients with cSDH met the inclusion criteria. Of these, 209 (4.9%) were treated with primary MMAE, 4050 (94.8%) were treated with primary surgery, 15 (0.35%) were treated using MMAE as an adjunct therapy, and 18 (0.42%) were treated using MMAE as a rescue following a failed surgical intervention. There were no significant differences in headache, facial weakness, and mortality between the groups. Patients who underwent primary MMAE had a significantly higher Charlson comorbidity index (P 0.0001) than those who underwent primary surgery. The need for surgical rescue was not significantly different between primary MMAE, adjunct MMAE, and rescue MMAE (P 0.05). Additionally, patients with primary surgery had significantly higher treatment failure than those with primary MMAE (odds ratio = 2.11, 95% confidence interval = 1.11-4.01, P = 0.020).This analysis suggests no significant difference in the need for surgical rescue, complication, or mortality between primary MMAE, adjunct MMAE, and rescue MMAE. Additionally, primary MMAE is associated with a significantly lower need for surgical rescue than primary surgery.

Background and purpose Previous studies suggest that mechanisms and outcomes in patients with COVID-19-associated stroke differ from those in patients with non-COVID-19-associated strokes, but there is limited comparative evidence focusing on these populations. The aim of this study, therefore, was to determine if a significant association exists between COVID-19 status with revascularization and functional outcomes following thrombectomy for large vessel occlusion (LVO), after adjustment for potential confounding factors. Methods A cross-sectional, international multicenter retrospective study was conducted in consecutively admitted COVID-19 patients with concomitant acute LVO, compared to a control group without COVID-19. Data collected included age, gender, comorbidities, clinical characteristics, details of the involved vessels, procedural technique, and various outcomes. A multivariable-adjusted analysis was conducted. Results In this cohort of 697 patients with acute LVO, 302 had COVID-19 while 395 patients did not. There was a significant difference (p < 0.001) in the mean age (in years) and gender of patients, with younger patients and more males in the COVID-19 group. In terms of favorable revascularization (modified Thrombolysis in Cerebral Infarction [mTICI] grade 3), COVID-19 was associated with lower odds of complete revascularization (odds ratio 0.33, 95% confidence interval [CI] 0.23-0.48; p < 0.001), which persisted on multivariable modeling with adjustment for other predictors (adjusted odds ratio 0.30, 95% CI 0.12-0.77; p = 0.012). Moreover, endovascular complications, in-hospital mortality, and length of hospital stay were significantly higher among COVID-19 patients (p < 0.001). Conclusion COVID-19 was an independent predictor of incomplete revascularization and poor functional outcome in patients with stroke due to LVO. Furthermore, COVID-19 patients with LVO were more often younger and had higher morbidity/mortality rates.

Background: Elevated blood pressure after endovascular thrombectomy (EVT) has been associated with an increased risk of hemorrhagic transformation and poor functional outcomes. However, the optimal hemodynamic management after EVT remains unknown, and the blood pressure course in the acute phase of ischemic stroke has not been well characterized. This study aimed to identify patient subgroups with distinct blood pressure trajectories after EVT and study their association with radiographic and functional outcomes. Methods: This multicenter retrospective cohort study included consecutive patients with anterior circulation large-vessel occlusion ischemic stroke who underwent EVT. Repeated time-stamped blood pressure data were recorded for the first 72 hours after thrombectomy. Latent variable mixture modeling was used to separate subjects into five groups with distinct postprocedural systolic blood pressure (SBP) trajectories. The primary outcome was functional status, measured on the modified Rankin Scale 90 days after stroke. Secondary outcomes included hemorrhagic transformation, symptomatic intracranial hemorrhage, and death. Results: Two thousand two hundred sixty-eight patients (mean age [±SD] 69±15, mean National Institutes of Health Stroke Scale 15±7) were included in the analysis. Five distinct SBP trajectories were observed: low (18%), moderate (37%), moderate-to-high (20%), high-to-moderate (18%), and high (6%). SBP trajectory group was independently associated with functional outcome at 90 days ( P P =0.0003 and adjusted odds ratio, 2.2 [95% CI, 1.5–3.2], P P =0.04). No significant association was found between trajectory group and hemorrhagic transformation. Conclusions: Patients with acute ischemic stroke demonstrate distinct SBP trajectories during the first 72 hours after EVT that have differing associations with functional outcome. These findings may help identify potential candidates for future blood pressure modulation trials.

To describe recent trends in treatment and outcomes of endovascular coil embolization and microsurgical clipping treatment strategies for ruptured intracranial aneurysms.Using International Classification of Diseases, Tenth Revision, codes, 1332 propensity-matched patients18 years old who underwent coiling or clipping were identified. Patient demographics, baseline characteristics, comorbidities, and clinical outcomes were evaluated within 1 year postoperatively. Pooled and individual studies of the International Classification of Diseases codes investigated differences in clinical outcomes owing to aneurysm location. Outcomes were mortality, intensive care, surgical complications, hydrocephalus, and vasospasm.After propensity matching for baseline characteristics and comorbidities, 666 patients were included in the coiling and clipping cohorts. There was no significant difference in 1-year mortality between cohorts. However, incidence of intensive care, surgical/medical complications, and vasospasm was significantly lower in the pooled coiling cohort (P = 0.02, P = 0.03, and P = 0.014) compared with the clipping cohort within 1 year postoperatively. Additionally, individual International Classification of Diseases code analysis revealed that coiling of anterior communicating artery aneurysms was associated with significantly fewer surgical/medical complications and hydrocephalus (P = 0.0008 and P = 0.015) and coiling of posterior communicating artery aneurysms was associated with substantially less vasospasm treatment (P = 0.034) compared with the respective clipping cohorts.Analysis revealed no difference in 1-year mortality between coiling and clipping. Clinical outcomes, including intensive care, surgical complications, and vasospasm, favored coiling regardless of aneurysm location. Patients with coiling of anterior communicating artery aneurysms had significantly less hydrocephalus and patients with coiling of posterior communicating artery aneurysms had substantially less vasospasm treatment within 1 year compared with the clipping cohort.

OBJECTIVE Surgical evacuation of chronic subdural hematoma (SDH) in cancer patients is often contraindicated owing to refractory thrombocytopenia. Middle meningeal artery embolization (MMAE) recently emerged as a potential alternative to surgical evacuation for patients with chronic SDH. The goal of this study was to evaluate the safety and efficacy of MMAE for chronic SDH in cancer patients with refractory thrombocytopenia. METHODS A multiinstitutional registry was reviewed for clinical and radiographic outcomes of cancer patients with transfusion-refractory thrombocytopenia and baseline platelet count < 75 K/µl, who underwent MMAE for chronic SDH. RESULTS MMAE was performed on a total of 31 SDHs in 22 patients, with a mean ± SD (range) platelet count of 42.1 ± 18.3 (9–74) K/µl. At the longest follow-up, 24 SDHs (77%) had reduced in size, with 15 (48%) showing > 50% reduction. Two patients required surgical evacuation after MMAE. There was only 1 procedural complication; however, 16 patients (73%) ultimately died of cancer-related complications. Median survival was significantly longer in the 16 patients with improved SDH than the 6 patients with worsened SDH after MMAE (185 vs 24 days, p = 0.029). Length of procedure, technical success rate, SDH size reduction, and complication rate were not significantly differ between patients who underwent transfemoral and transradial approaches. CONCLUSIONS Transfemoral or transradial MMAE is a potential therapeutic option for thrombocytopenic cancer patients with SDH. However, treatment benefit may be marginal for patients with high disease burden and limited life expectancy. A prospective trial is warranted to address these questions.

Funder: NIH U18EB029353, NSF GRFP, Funder: NIH U18EB029353, Funder: NIH R01DE021798, NSF GRFP, Funder: NIH R01DE021798, Implantable bioelectronic devices for the simulation of peripheral nerves could be used to treat disorders that are resistant to traditional pharmacological therapies. However, for many nerve targets, this requires invasive surgeries and the implantation of bulky devices (about a few centimetres in at least one dimension). Here we report the design and in vivo proof-of-concept testing of an endovascular wireless and battery-free millimetric implant for the stimulation of specific peripheral nerves that are difficult to reach via traditional surgeries. The device can be delivered through a percutaneous catheter and leverages magnetoelectric materials to receive data and power through tissue via a digitally programmable 1 mm × 0.8 mm system-on-a-chip. Implantation of the device directly on top of the sciatic nerve in rats and near a femoral artery in pigs (with a stimulation lead introduced into a blood vessel through a catheter) allowed for wireless stimulation of the animals' sciatic and femoral nerves. Minimally invasive magnetoelectric implants may allow for the stimulation of nerves without the need for open surgery or the implantation of battery-powered pulse generators.

BackgroundThe pipeline embolization device (PED; Medtronic) has presented as a safe and efficacious treatment for small- and medium-sized intracranial aneurysms. Independently adjudicated long-term results of the device in treating these lesions are still indeterminate. We present 3-year results, with additional application of a flow diverter specific occlusion scale.MethodsPREMIER (prospective study on embolization of intracranial aneurysms with pipeline embolization device) is a prospective, single-arm trial. Inclusion criteria were patients with unruptured wide-necked intracranial aneurysms ≤12 mm. Primary effectiveness (complete aneurysm occlusion) and safety (major neurologic event) endpoints were independently monitored and adjudicated.ResultsAs per the protocol, of 141 patients treated with a PED, 25 (17.7%) required angiographic follow-up after the first year due to incomplete aneurysm occlusion. According to the Core Radiology Laboratory review, three (12%) of these patients progressed to complete occlusion, with an overall rate of complete aneurysm occlusion at 3 years of 83.3% (115/138). Further angiographic evaluation using the modified Cekirge–Saatci classification demonstrated that complete occlusion, neck residual, or aneurysm size reduction occurred in 97.1%. The overall combined safety endpoint at 3 years was 2.8% (4/141), with only one non-debilitating major event occurring after the first year. There was one case of aneurysm recurrence but no cases of delayed rupture in this series.ConclusionsThe PED device presents as a safe and effective modality in treating small- and medium-sized intracranial aneurysms. The application of a flow diverter specific occlusion classification attested the long-term durability with higher rate of successful aneurysm occlusion and no documented aneurysm rupture.Trial registrationNCT02186561.

The Woven EndoBridge (WEB) device (Terumno Corp. [parent company of Microvention]) was approved by the U.S. Food and Drug Administration as the first intrasaccular device for intracranial aneurysm treatment in December 2018. Its use has become more common since then, but both trial results and postmarket experiences have raised questions about the efficacy in achieving complete aneurysm obliteration. Retreatment after WEB embolization has not been extensively discussed. OBJECTIVE: To discuss the incidence and retreatment of aneurysms after initial WEB embolization. METHODS: Retrospective review across 13 institutions identified all occurrences of WEB retreatment within neurovascular databases. Details regarding demographics, aneurysm characteristics, treatment considerations, clinical outcomes, and aneurysm occlusion were obtained and analyzed. RESULTS: Thirty aneurysms were retreated in 30 patients in a cohort of 342 WEB-treated aneurysms. The retreatment rate was 8.8%. Endovascular methods were used for 23 cases, and 7 were treated surgically. Two aneurysms presented with rehemorrhage after initial WEB embolization. Endovascular treatments included stent-assisted coiling (12), flow diversion (7), coiling (2), PulseRider (Johnson & Johnson)–assisted coiling (1), and additional WEB placement (1). Surgical treatments included primary clipping (6) and Hunterian ligation (1). There were no major complications within the study group. CONCLUSION: WEB retreatments were successfully performed by a variety of techniques, including stent-assisted coiling, clipping, and flow diversion as the most common. These procedures were performed safely with subsequent obliteration of most aneurysms. The potential need for retreatment of aneurysms should be considered during primary WEB treatments.

Background: Mechanical thrombectomy is standard of care for acute ischemic stroke secondary to LVO however MT failure (MTF) occurs in approximately 15% of cases. Objective: Investigate patient and procedural characteristics that predict MTF. Methods: Retrospective review of prospectively collected, Stroke Thrombectomy and Aneurysm Registry. Patients who underwent MT for LVO were included and categorized by MT Success (MTS) or MTF, defined as mTICI≥2b or Results: A total of 8452 patients were analyzed, and 1301(15.4%) experienced MTF.MTF patients were older(73 vs.71, p=0.008)had higher poor premorbid mRS(10.8% vs 8.4%, p=0.17).Onset to puncture was greater in MTF group(442 vs.411 min, p=0.006).There were more ICA occlusions(15.6% vs. 13.5%)and basilar occlusions(7.8% vs.6.2%)in the MTF group and more M1 occlusions(42.2%vs.37.5%)in the MTS group (p Conclusion: MTF is associated with more complications and worse outcome. Final use of aspiration and rescue intracranial stenting may increase chances of recanalization.

BackgroundThe Surpass flow diverter was developed to treat intracranial aneurysms not amenable to standard treatment. Indications for use allow placement in the internal carotid artery to the terminus, including the communicating artery segment.MethodsThe Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms (SCENT) trial is an international, multicenter, prospective, non-randomized trial comparing the outcomes of Surpass flow diverter treatment with historic control designed to evaluate the effectiveness and safety of Surpass for the treatment of wide neck (≥4 mm) large or giant intracranial aneurysms ≥10 mm. The primary effectiveness endpoint is the percentage of subjects with 100% aneurysm occlusion without significant stenosis of the parent artery and without retreatment of the target aneurysm at 12 months. The primary safety endpoint is the percentage of subjects experiencing neurologic death or major ipsilateral stroke at 12 months. We report the effectiveness and safety of flow diversion in the subgroup of posterior communicating artery (PComA) aneurysms.ResultsOf the 180 patients treated, 38 harbored a PComA aneurysm. Mean aneurysm size was 12.2 mm and mean neck width was 4.8 mm. The mean number of Surpass devices used was 1.1 per procedure, with 94.7% of aneurysms treated with one flow diverter. The 12 month primary effectiveness rate was 73.7% (28/38). At 36 months, 68.4% (26/38) of aneurysms remained completely occluded. The 12 month major ipsilateral stroke or neurological death rate was 10.5%. No patients with PComA occlusion after flow diverter placement (54.5%) had clinical sequelae.ConclusionsSCENT demonstrated acceptable 12 month effectiveness of flow diversion in PComA aneurysms. Despite associated PComA occlusions in many cases, arterial occlusions were clinically silent.Trial registration numberURL: https://www.clinicaltrials.gov. Unique identifier: NCT01716117.

BackgroundData regarding the safety and efficacy of flow diverting stents (FDS) in the treatment of middle cerebral artery (MCA) bifurcation aneurysms are scarce and limited to small single center series, with particular concern for increased risk of ischemic complications with jailing one of the M2 branches.MethodsProspectively-maintained databases at six North American and European centers were queried for patients harboring MCA bifurcation aneurysms undergoing treatment with FDS (2011–2018). The pertinent clinical and radiographic data were collected and analyzed.Results87 patients (median age 60 years, 69% females) harboring 87 aneurysms were included. The majority of aneurysms were unruptured (79%); 75.9% were saccular with a median maximal diameter of 8.5 mm. Radiographic imaging follow-up was available in 88.5% of cases at a median of 16.3 months post-treatment, showing complete occlusion in 59% and near complete occlusion (90–99%) in 18% of aneurysms. The overall rate of ischemic and hemorrhagic complications was 8% and 1.1%, respectively. Symptomatic and permanent complications were encountered in 5.7% and 2.3% of patients respectively, with retreatment pursued in 2.3% of patients. Jailed branch occlusion was detected in 11.5% of cases, with clinical sequelae in 2.3%. Last follow-up modified Rankin Scale of 0–2 was noted in 96.8% of patients. On multivariate analysis, male sex was the only independent predictor of aneurysmal persistence at last follow-up imaging (p=0.019).ConclusionFDS treatment for MCA bifurcation aneurysms is feasible, with comparable safety and efficacy profiles to other available endovascular options when utilized in carefully selected aneurysms. Jailing of M2 branches was not associated with a higher risk of post-procedural ischemic complications.

OBJECTIVE In select patients, extracranial-intracranial (EC-IC) bypass remains an important tool for cerebral revascularization. Traditionally, superficial temporal artery–middle cerebral artery (STA-MCA) bypass was performed using one limb of the STA only. In an attempt to augment flow and to direct flow to different ischemic areas of the brain, the authors adopted a “double-barrel” technique in which both branches of the STA are used to revascularize distinct MCA territories. METHODS A series of consecutive double-barrel STA-MCA bypasses performed between 2010 and 2020 were reviewed. Each anastomosis was directed to augment flow to a territory most at risk based on preoperative perfusion studies, cerebral angiography, and intraoperative indocyanine green data. CT perfusion and CTA were routinely used to evaluate postoperative augmentation and graft patency. Patient perioperative outcomes, surgical complications, and modified Rankin Scale (mRS) scores at the last follow-up were reported. RESULTS Forty-four patients (16 males, 28 females) successfully underwent double-barrel STA-MCA bypass on 54 cerebral hemispheres: 28 operations were for moyamoya disease, 23 for atherosclerotic disease refractory to medical therapy, 2 for complex cerebral aneurysms, and 1 for carotid occlusion as a sequela of cavernous meningioma growth. Ten patients underwent multiple operations, 9 of whom had moyamoya disease/syndrome, with the subsequent operation on the contralateral hemisphere. The average patient age at surgery was 45.1 years (range 14–73 years), with a mean follow-up time of 22.1 months. Intraoperative graft patency was confirmed in 100% of cases, and 101 (98.1%) of the 103 anastomoses with imaging follow-up were patent. Perfusion to the revascularized hemisphere was improved in 88.2% of cases. Perioperative ischemic and hemorrhagic complications occurred in 8 procedures (2 were asymptomatic), whereas remote ischemic and hemorrhagic events occurred in 7 cases. There was no mortality in the series, and the mean patient mRS scores were 1.72 at presentation and 1.15 at the last follow-up. CONCLUSIONS The high rates of intraoperative and postoperative patency support the feasibility of dual-anastomosis STA-MCA bypass for revascularization. The perioperative complication rate is not significantly different from that of single-anastomosis bypass. The functional outcomes at follow-up and perfusion improvement postoperatively support the efficacy and safety of this method as a treatment strategy.

IntroductionThe Walrus balloon guide catheter (BGC) is a new generation of BGC, designed to eliminate conventional limitations during mechanical thrombectomy.ObjectiveTo report a multi-institutional experience using this BGC for proximal flow control (PFC) in the setting of carotid artery angioplasty/stenting (CAS) in elective (eCAS) and tandem strokes (tCAS).MethodsProspectively maintained databases at 8 North American centers were queried to identify patients with cervical carotid disease undergoing eCAS/tCAS with a Walrus BGC.Results110 patients (median age 68, 64.6% male), 80 (72.7%) undergoing eCAS and 30 (27.3%) tCAS procedures, were included (median cervical carotid stenosis 90%; 46 (41.8%) with contralateral stenosis). Using a proximal flow-arrest technique in 95 (87.2%) and flow-reversal in 14 (12.8%) procedures, the Walrus was navigated into the common carotid artery successfully in all cases despite challenging arch anatomy (31, 28.2%), with preferred femoral access (103, 93.6%) and in monitored anesthesia care (90, 81.8%). Angioplasty and distal embolic protection devices (EPDs) were used in 91 (83.7%) and 58 (52.7%) procedures, respectively. tCAS led to a modified Thrombolysis in Cerebral Infarction 2b/3 in all cases. Periprocedural ischemic stroke (up to 30 days postoperatively) rate was 0.9% (n=1) and remote complications occurred in 2 (1.8%) cases. Last follow-up modified Rankin Scale score of 0–2 was seen in 95.3% of eCAS cohort, with no differences in complications in the eCAS subgroup between PFC only versus PFC and distal EPD (median follow-up 4.1 months).ConclusionWalrus BGC for proximal flow control is safe and effective during eCAS and tCAS. Procedural success was achieved in all cases, with favorable safety and functional outcomes on short-term follow-up.

Background Open surgery has traditionally been preferred for the management of bifurcation middle cerebral artery (MCA) aneurysms. Flow diverting stents present a novel endovascular strategy for aneurysm treatment. Objective To add to the limited literature describing the outcomes and complications in the use of flow diverters for the treatment of these complex aneurysms. Methods This is a multicenter retrospective review of MCA bifurcation aneurysms undergoing flow diversion. We assessed post-treatment radiological outcomes and both thromboembolic and hemorrhagic complications. Results We reviewed the outcomes of 54 aneurysms treated with flow diversion. Four (7.4%) of the aneurysms had a history of rupture (3 remote and 1 acute). Fourteen (25.9%) of the aneurysms already underwent either open surgery or coiling prior to flow diversion. A total of 36 out of the 45 aneurysms (80%) with available follow-up data had adequate aneurysm occlusion with a median follow-up time of 12 mo. There were no hemorrhagic complications but 16.7% (9/54) had thromboembolic complications. Conclusion Flow diverting stents may be a viable option for the endovascular treatment of complex bifurcation MCA aneurysms. However, compared to published series on the open surgical treatment of this subset of aneurysms, flow diversion has inferior outcomes and are associated with a higher rate of complications.

Blood blister aneurysms are small, thin-walled, rapidly growing side-wall aneurysms that have proved particularly difficult to treat, and evidence-based guidance for treatment strategies is lacking. A systematic review and meta-analysis was performed to aggregate the available data and compare the 3 primary treatment modalities.We performed a comprehensive literature search according to PRISMA guidelines followed by an indirect meta-analysis that compares the safety and efficacy of surgical, flow-diverting stents (FDS), and other endovascular approaches for the treatment of ruptured blood blister aneurysms.A total of 102 studies were included for quantitative synthesis, with sample sizes of 687 treated surgically, 704 treated endovascularly without FDS, and 125 treated via flow diversion. Comparatively, FDS achieved significantly reduced rates of perioperative retreatment compared with both surgical (P = 0.025) and non-FDS endovascular (P0.001). The FDS subgroup also achieved a significantly lower incidence of perioperative rebleed (P 0.001), perioperative hydrocephalus (P = 0.012), postoperative infarction (P = 0.002), postoperative hydrocephalus (P0.001), and postoperative vasospasm (P = 0.002) compared with those patients in the open surgical subgroup. Although no significant differences were found among groups on the basis of functional outcomes, angiographic outcomes detailed by rates of radiographic complete occlusion were highest for surgical (90.7%, 262/289) and FDS (89.1%, 98/110) subgroups versus the non-FDS endovascular subgroup (82.7%, 268/324).Flow diversion seems to be an effective treatment strategy for ruptured blood blister aneurysms, with lower rates of perioperative complications compared with surgical and other endovascular techniques, but studies investigating long-term outcomes after flow diversion warrant further study.