Development of an Injectable, ECM-Derivative Embolic for the Treatment of Cerebral Saccular Aneurysms.

Cerebral aneurysms are a source of neurological morbidity and mortality, most often as a result of rupture. The most common approach for treating aneurysms involves endovascular embolization using nonbiodegradable medical devices, such as platinum coils. However, the need for retreatment due to the recanalization of coil-treated aneurysms highlights the importance of exploring alternative solutions. In this study, we propose an injectable extracellular matrix-derived embolic formed in situ by Michael addition of gelatin-thiol (Gel-SH) and hyaluronic acid vinyl sulfone (HA-VS) that may be delivered with a therapeutic agent (here, RADA-SP) to fill and remodel aneurysmal tissue without leaving behind permanent foreign bodies. The injectable embolic material demonstrated rapid gelation under physiological conditions, forming a highly porous structure and allowing for cellular infiltration. The injectable embolic exhibited thrombogenic behavior in vitro that was comparable to that of alginate injectables. Furthermore, in vivo studies in a murine carotid aneurysm model demonstrated the successful embolization of a saccular aneurysm and extensive cellular infiltration both with and without RADA-SP at 3 weeks, with some evidence of increased vascular or fibrosis markers with RADA-SP incorporation. The results indicate that the developed embolic has inherent potential for acutely filling cerebrovascular aneurysms and encouraging the cellular infiltration that would be necessary for stable, chronic remodeling.

Dural arteriovenous fistulas are not observed to convert to a higher grade after partial embolization.

OBJECTIVE: Borden-Shucart type I dural arteriovenous fistulas (dAVFs) lack cortical venous drainage and occasionally necessitate intervention depending on patient symptoms. Conversion is the rare transformation of a low-grade dAVF to a higher grade. Factors associated with increased risk of dAVF conversion to a higher grade are poorly understood. The authors hypothesized that partial treatment of type I dAVFs is an independent risk factor for conversion. METHODS: The multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research database was used to perform a retrospective analysis of all patients with type I dAVFs. RESULTS: Three hundred fifty-eight (33.2%) of 1077 patients had type I dAVFs. Of those 358 patients, 206 received endovascular treatment and 131 were not treated. Two (2.2%) of 91 patients receiving partial endovascular treatment for a low-grade dAVF experienced conversion to a higher grade, 2 (1.5%) of 131 who were not treated experienced conversion, and none (0%) of 115 patients who received complete endovascular treatment experienced dAVF conversion. The majority of converted dAVFs localized to the transverse-sigmoid sinus and all received embolization as part of their treatment. CONCLUSIONS: Partial treatment of type I dAVFs does not appear to be significantly associated with conversion to a higher grade.

Assessment of the safety and efficacy of the Zoom 45 and 55 reperfusion catheters for medium and distal mechanical thrombectomies: A multi-institutional study.

INTRODUCTION: The Zoom aspiration catheters harbor novel dimensions and construction to enhance trackability and deliverability. In addition, a beveled tip may improve thrombus interaction and aspiration force for a set inner diameter. This study evaluates their utility in medium and distal vessel occlusions. OBJECTIVE: To evaluate the safety and efficacy of Zoom 45 and 55 aspiration catheters in medium and distal vessel thrombectomy. METHODS: Patients treated for distal vessel occlusions via mechanical thrombectomy utilizing either the Zoom 45/55 catheter or a historical control catheter between 2021-2022 at two institutions were included in this study. Medium and distal occlusions were defined as any anterior or posterior cerebral artery branch as well as the M2-4 segment of the middle cerebral artery (MCA). Preprocedural, procedural, and postprocedural variables were obtained. RESULTS: Thirty-eight patients underwent thrombectomy with Zoom 45 or 55 catheters; four had multiple occluded vessels. Occlusion location included the M2 in 32 cases, M3-4 in 7 cases, A2 in 2 cases and P2 in 1 case. The mean number of passes per occlusion was 1.6 and overall successful reperfusion (TICI 2b or greater) was achieved in 84 % of cases. There were no symptomatic procedure-related complications such as perforation or post-procedural symptomatic ICH. Modified Rankin scores rates of 0-2, 3-5, and 6 at three months post-procedure were 35.7 %, 21.4 %, and 42.9 %, respectively. CONCLUSIONS: The Zoom beveled tip aspiration catheters are safe and effective for more challenging medium and distal vessel occlusions.

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.

A Future Blood Test to Detect Cerebral Aneurysms.

Intracranial aneurysms are reported to affect 2-5% of the population. Despite advances in the surgical management of this disease, diagnostic technologies have marginally improved and still rely on expensive or invasive imaging procedures. Currently, there is no blood-based test to detect cerebral aneurysm formation or quantify the risk of rupture. The aim of this review is to summarize current literature on the mechanism of aneurysm formation, specifically studies relating to inflammation, and provide a rationale and commentary on a hypothetical future blood-based test. Efforts should be focused on clinical-translational approaches to create an assay to screen for cerebral aneurysm presence and risk-stratify patients to allow for superior treatment timing and management. Cerebral Aneurysm Blood Test Considerations: There are multiple caveats to development of a putative blood test to detect cerebral aneurysm presence.

Dolichoectatic vertebrobasilar aneurysms: a systematic review and meta-analysis of management strategies and outcomes.

OBJECTIVE: The aim of this study was to describe the efficacy, clinical outcomes, and complications of open cerebrovascular surgery, endovascular surgery, and conservative management of dolichoectatic vertebrobasilar aneurysms (DVBAs). METHODS: Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane databases according to PRISMA guidelines. A meta-analysis was conducted for clinical presentation, treatment protocols, and clinical outcomes-good (improved or stable clinical status) or poor (deteriorated clinical status or death)-and mortality rates. RESULTS: The 9 identified articles described 41 cases (27.5%) of open cerebrovascular surgery, 61 endovascular procedures (40.9%), and 47 cases (31.5%) of conservative management for DVBAs. The total cohort had a good outcome rate of 51.9% (95% CI 28.3%-74.6%), a poor outcome rate of 45.5% (95% CI 23.0%-70.1%), and a mortality rate of 22.3% (95% CI 11.8%-38.0%). The treatment groups had comparable good clinical outcome rates (open cerebrovascular surgery group: 24.7% [95% CI 2.9%-78.2%]; endovascular surgery group: 69.0% [95% CI 28.7%-92.5%]; conservative management group: 57.7% [95% CI 13.0%-92.5%]; p = 0.19) and poor outcome rates (open vascular surgery group: 75.3% [95% CI 21.8%-97.1%]; endovascular surgery group: 27.2% [95% CI 5.6%-0.70.2%]; conservative management group: 39.9% [95% CI 9.1%-81.6%]; p = 0.15). The treatment groups also had comparable mortality rates (open vascular surgery group: 39.5% [95% CI 11.4%-76.8%]; endovascular surgery group: 15.8% [95% CI 4.4%-43.0%]; conservative management group: 19.2% [95% CI 6.8%-43.5%]; p = 0.23). CONCLUSIONS: The current study of DVBAs illustrated poor outcomes and high mortality rates regardless of the treatment modality. The subgroup analysis showed heterogeneity among the subgroups and advice for personalized management.

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.

Risk of Early Versus Later Rebleeding From Dural Arteriovenous Fistulas With Cortical Venous Drainage.

BACKGROUND: Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time. Our objective was to quantify the relative incidence of rebleeding in the early and later periods following hemorrhage. METHODS: Patients with dural arteriovenous fistula and cortical venous drainage presenting with hemorrhage were identified from the multinational CONDOR (Consortium for Dural Fistula Outcomes Research) database. Natural history follow-up was defined as time from hemorrhage to first treatment, rebleed, or last follow-up. Rebleeding in the first 2 weeks and first year were compared using incidence rate ratio and difference. RESULTS: Of 1077 patients, 250 met the inclusion criteria and had 95 cumulative person-years natural history follow-up. The overall annualized rebleed rate was 7.3% (95% CI, 3.2-14.5). The incidence rate of rebleeding in the first 2 weeks was 0.0011 per person-day; an early rebleed risk of 1.6% in the first 14 days (95% CI, 0.3-5.1). For the remainder of the first year, the incidence rate was 0.00015 per person-day; a rebleed rate of 5.3% (CI, 1.7-12.4) over 1 year. The incidence rate ratio was 7.3 (95% CI, 1.4-37.7; P, 0.026). CONCLUSIONS: The risk of rebleeding of a dural arteriovenous fistula with cortical venous drainage presenting with hemorrhage is increased in the first 2 weeks justifying early treatment. However, the magnitude of this increase may be considerably lower than previously thought. Treatment within 5 days was associated with a low rate of rebleeding and appears an appropriate timeframe.

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.

Outcome Following Hemorrhage From Cranial Dural Arteriovenous Fistulae: Analysis of the Multicenter International CONDOR Registry.

Background and Purpose: Dural arteriovenous fistulae can present with hemorrhage, but there remains a paucity of data regarding subsequent outcomes. We sought to use the CONDOR (Consortium for Dural Arteriovenous Fistula Outcomes Research), a multi-institutional registry, to characterize the morbidity and mortality of dural arteriovenous fistula­related hemorrhage. Methods: A retrospective review of patients in CONDOR who presented with dural arteriovenous fistula­related hemorrhage was performed. Patient characteristics, clinical follow-up, and radiographic details were analyzed for associations with poor outcome (defined as modified Rankin Scale score ≥3). Results: The CONDOR dataset yielded 262 patients with incident hemorrhage, with median follow-up of 1.4 years. Poor outcome was observed in 17.0% (95% CI, 12.3%­21.7%) at follow-up, including a 3.6% (95% CI, 1.3%­6.0%) mortality. Age and anticoagulant use were associated with poor outcome on multivariable analysis (odds ratio, 1.04, odds ratio, 5.1 respectively). Subtype of hemorrhage and venous shunting pattern of the lesion did not affect outcome significantly. Conclusions: Within the CONDOR registry, dural arteriovenous fistula­related hemorrhage was associated with a relatively lower morbidity and mortality than published outcomes from other arterialized cerebrovascular lesions but still at clinically consequential rates.

New Class of Radially Adjustable Stentrievers for Acute Ischemic Stroke: Primary Results of the Multicenter TIGER Trial.

[Figure: see text].

Management of tandem occlusions in patients who receive rtPA.

BACKGROUND: Tandem occlusions exist in 17-32% of large vessel occlusion (LVO) strokes. A significant concern is bleeding when carotid stenting is performed in tandem with thrombectomy due the administration of antiplatelet agents such as glycoprotein IIb/IIIa inhibitors (GP2b3aI) after receiving rtPA, but data are limited in this setting. METHODS: A mutlicenter, retrospective chart review was conducted at two comprehensive stroke centers to assess the safety and efficacy of using GP2b3aI to facilitate carotid stent placement simultaneously with endovascular thrombectomy in patients who have received rtPA. RESULTS: Overall, 32 patients were included in this study, with average age of 66.3 ± 10.4 years and predominantly male (87.5%). The cause of stroke was mostly large artery atherosclerosis (59.4%) and the thrombectomy target vessels were typically first- or second segment middle cerebral artery (37.5% and 31.3%). Time from symptom onset to rtPA bolus was 1.8 h [interquartile range (IQR) 1.5-2.7], rtPA bolus to first pass was 2 h [IQR 1.5-3.1], rtPA bolus to GP2b3aI bolus was 2 h [IQR 1.6-3.5], and rtPA bolus to aspirin and clopidogrel administration was 4.3 h [IQR 2.6-8.9] and 6.6 h [IQR 4.5-11.6] respectively. No patients had acute in-stent thrombosis or post-op bleeding from the access site. Two patients (6.3%) had significant hemorrhagic conversion. CONCLUSION: The use of GP2b3aI in the setting of tandem occlusions that required emergent stent placement post-rtPA appears safe and effective. Given the small sample size, these findings should be interpreted cautiously, and need to be confirmed in a larger patient population.

Does stroke etiology influence outcome in the posterior circulation? An analysis of 107 consecutive acute basilar occlusion thrombectomies.

OBJECTIVE: Acute basilar artery occlusion (BAO) harbors a more guarded prognosis after thrombectomy compared with anterior circulation large-vessel occlusion. Whether this is a function of a greater proportion of atherosclerotic/intrinsic lesions is not well studied. The authors aimed to elucidate the prevalence and predictors of intracranial intrinsic atherosclerotic disease in patients with acute BAO and to compare angiographic and clinical outcomes between patients with BAO secondary to embolic versus intrinsic disease. METHODS: A prospectively maintained stroke database was reviewed for all patients presenting between January 2013 and December 2019 to a tertiary care academic comprehensive stroke center with acute, nontandem BAO. Patient data were extracted, subdivided by stroke mechanism and treatment modality (embolic [thrombectomy only] and intrinsic [thrombectomy + stenting]), and angiographic and clinical results were compared. RESULTS: Of 107 patients, 83 (78%) had embolic occlusions (thrombectomy only) and 24 (22%) had intrinsic disease (thrombectomy + stenting). There was no significant difference in patient age, presenting National Institutes of Health Stroke Scale score, time to presentation, selected medical comorbidities (hypertension, hyperlipidemia, diabetes, and atrial fibrillation), prior stroke, and posterior circulation Alberta Stroke Program Early CT Score. Patients with intrinsic disease were more likely to be active smokers (50% vs 26%, p = 0.04) and more likely to be male (88% vs 48%, p = 0.001). Successful recanalization, defined as a modified Thrombolysis in Cerebral Infarction (mTICI) grade of 2b or 3, was achieved in 90% of patients and did not differ significantly between the embolic versus intrinsic groups (89% vs 92%, p > 0.99). A 90-day good outcome (modified Rankin Scale [mRS] score 0-2) was found in 37% of patients overall and did not differ significantly between the two groups (36% vs 41%, p = 0.41). Mortality was 40% overall and did not significantly differ between groups (41% vs 36%, p = 0.45). CONCLUSIONS: In the current study, demographic and clinical results for acute BAO showed that compared with intrinsic disease, thromboembolic disease is a more common mechanism of acute BAO, with 78% of patients undergoing thrombectomy alone. However, there was no significant difference in revascularization and outcome results between patients with embolic disease and those with intrinsic disease.

Conventional Angiography in the Assessment of Recently Symptomatic Patients with Ipsilateral Carotid Stenosis.

BACKGROUND AND PURPOSE: Benefits of revascularization for moderate and severe (≥50%) carotid stenosis were established based on digital subtraction angiography (DSA). We aimed to assess the discrepancy between invasive and non-invasive angiography in a consecutive, prospective cohort of patients with recent stroke and non-invasive imaging suggesting ≥50% ipsilateral carotid stenosis. MATERIALS AND METHODS: We reviewed prospectively-collected data for consecutive patients admitted with recent stroke/TIA and ≥50% ipsilateral carotid stenosis on non-invasive imaging over 28 months. All patients underwent DSA to confirm the degree of stenosis per NASCET criteria. All patients with <50% stenosis by DSA were treated with medical therapy only and their recurrent event rates were assessed at 6 months. RESULTS: 148 symptomatic patients with ≥50% ipsilateral carotid stenosis on CTA (82%) and MRA (18%) underwent DSA to confirm degree of stenosis. Median age was 73 years and 64% were male. DSA demonstrated <50% stenosis in 28 patients (19%). Median presenting NIHSS was 1 (IQR 0-3). Median carotid stenosis evaluated by non-invasive imaging was 70% (IQR 60-85%) and by DSA was 40% (IQR 30-45%). One of 28 patients (4%) experienced recurrent nondisabling stroke (NIHSS 1) after stopping dual antiplatelet therapy. CONCLUSION: In nearly one-in-five cases with recent stroke due to ipsilateral carotid stenosis deemed to be candidates for revascularization based on CTA or MRA, DSA led to institution of medical therapy only due to insufficiently severe stenosis. In patients treated with medical therapy based on the findings of <50% stenosis on DSA, the rate of recurrent stroke is low.

Middle meningeal artery embolization treatment of nonacute subdural hematomas in the elderly: a multiinstitutional experience of 151 cases.

OBJECTIVE: The incidence of already common chronic subdural hematomas (CSDHs) and other nonacute subdural hematomas (NASHs) in the elderly is expected to rise as the population ages over the coming decades. Surgical management is associated with recurrence and exposes elderly patients to perioperative and operative risks. Middle meningeal artery (MMA) embolization offers the potential for a minimally invasive, less morbid treatment in this age group. The clinical and radiographic outcomes after MMA embolization treatment for NASHs have not been adequately described in elderly patients. In this paper, the authors describe the clinical and radiographic outcomes after 151 cases of MMA embolization for NASHs among 121 elderly patients. METHODS: In a retrospective review of a prospectively maintained database across 15 US academic centers, the authors identified patients aged ≥ 65 years who underwent MMA embolization for the treatment of NASHs between November 2017 and February 2020. Patient demographics, comorbidities, clinical and radiographic factors, treatment factors, and clinical outcomes were abstracted. Subgroup analysis was performed comparing elderly (age 65-79 years) and advanced elderly (age > 80 years) patients. RESULTS: MMA embolization was successfully performed in 98% of NASHs (in 148 of 151 cases) in 121 patients. Seventy elderly patients underwent 87 embolization procedures, and 51 advanced elderly patients underwent 64 embolization procedures. Elderly and advanced elderly patients had similar rates of embolization for upfront (46% vs 61%), recurrent (39% vs 33%), and prophylactic (i.e., with concomitant surgical intervention; 15% vs 6%) NASH treatment. Transfemoral access was used in most patients, and the procedure time was approximately 1 hour in both groups. Particle embolization with supplemental coils was most common, used in 51% (44/87) and 44% (28/64) of attempts for the elderly and advanced elderly groups, respectively. NASH thickness decreased significantly from initial thickness to 6 weeks, with additional decrease in thickness observed in both groups at 90 days. At longest follow-up, the treated NASHs had stabilized or improved in 91% and 98% of the elderly and advanced elderly groups, respectively, with > 50% improvement seen in > 60% of patients for each group. Surgical rescue was necessary in 4.6% and 7.8% of cases, and the overall mortality was 8.6% and 3.9% for elderly and advanced elderly patients, respectively. CONCLUSIONS: MMA embolization can be used safely and effectively as an alternative or adjunctive minimally invasive treatment for NASHs in elderly and advanced elderly patients.

Last Electrically Well: Intraoperative Neurophysiological Monitoring for Identification and Triage of Large Vessel Occlusions.

INTRODUCTION: Intra-operative stroke (IOS) is associated with poor clinical outcome as detection is often delayed and time of symptom onset or patient's last known well (LKW) is uncertain. Intra-operative neurophysiological monitoring (IONM) is uniquely capable of detecting onset of neurological dysfunction in anesthetized patients, thereby precisely defining time last electrically well (LEW). This novel parameter may aid in the detection of large vessel occlusion (LVO) and prompt treatment with endovascular thrombectomy (EVT). METHODS: We performed a retrospective analysis of a prospectively maintained AIS and LVO database from May 2018-August 2019. Inclusion criteria required any surgical procedure under general anesthesia (GA) utilizing EEG (electroencephalography) and/or SSEP (somatosensory evoked potentials) monitoring with development of intraoperative focal persistent changes using predefined alarm criteria and who were considered for EVT. RESULT: Five cases were identified. LKW to closure time ranged from 66 to 321 minutes, while LEW to closure time ranged from 43 to 174 min. All LVOs were in the anterior circulation. Angiography was not pursued in two cases due to large established infarct (both patients expired in the hospital). EVT was pursued in two cases with successful recanalization and spontaneous recanalization was noted in one patient (mRS 0-3 at 90 days was achieved in all 3 cases). CONCLUSIONS: This study demonstrates that significant IONM changes can accurately identify patients with an acute LVO in the operative setting. Given the challenges of recognizing peri-operative stroke, LEW may be an appropriate surrogate to quickly identify and treat IOS.

Thrombectomy after in-house stroke in the transfer population.

BACKGROUND: Patients with large-vessel occlusion (LVO) who initially present to a non-thrombectomy-capable center ("spoke") have worse outcomes than those presenting directly to a thrombectomy-capable center ("hub"). Furthermore, patients who suffer in-hospital strokes (IHS) suffer worse outcomes than those suffering strokes in the community. Data on patients who suffer IHS at a spoke hospital is lacking. We aim to characterize this particularly vulnerable population, define their outcomes, and compare them to patients who develop IHS at a hub institution. METHODS: We retrospectively reviewed prospectively collected data from patients suffering an IHS at a spoke hospital who were then transferred to the hub hospital for endovascular therapy (EVT). We then compared outcomes of these patients under EVT after developing IHS at the hub institution. RESULTS: A total of 108 IHS patients met inclusion criteria: 91 (84%) at a spoke facility and 17 (16%) at the hub facility. Baseline characteristics and reason for hospital admission were comparable between the two groups. Time from imaging to IV-tPA administration (17 vs. 70 min, p = 0.01) and time to EVT (120 vs. 247 min, p = 0.001) were significantly shorter in the hub group. More patients had a 90 day-mRS of 0-3 in the hub group than the spoke group (57% vs 22%, p < 0.05). CONCLUSION: Patients undergoing EVT after suffering IHS at a spoke hospital have significantly higher rates of poor outcomes compared to patients who suffer IHS at a hub hospital. Prolonged time delays in the initiation of IV-tPA and EVT represent areas of improvement.

A comparison of digital subtraction angiography and computed tomography angiography for the diagnosis of penetrating cerebrovascular injury.

OBJECTIVE: Penetrating cerebrovascular injury (PCVI) is a subset of traumatic brain injury (TBI) comprising a broad spectrum of cerebrovascular pathology, including traumatic pseudoaneurysms, direct arterial injury, venous sinus stenosis or occlusion, and traumatic dural arteriovenous fistulas. These can result in immediate or delayed vascular injury and consequent neurological morbidity. Current TBI guidelines recommend cerebrovascular imaging for detection, but there is no consensus on the optimum modality. The aim of this retrospective cohort study was to compare CT angiography (CTA) and digital subtraction angiography (DSA) for the diagnosis of PCVI. METHODS: The records of all patients presenting to two level I trauma centers in the United States between January 2010 and July 2016 with penetrating head or neck trauma were reviewed. Only those who had undergone both CTA and DSA were included. Clinical and neuroimaging data were collected, and PCVIs were stratified using a modified Biffl grading scheme. DSA and CTA results were then compared. RESULTS: Of 312 patients with penetrating trauma over the study period, 56 patients (91% male, mean age 32 years) with PCVI met inclusion criteria and constituted the study cohort. The mechanism of injury was a gunshot wound in 86% (48/56) of patients. Twenty-four (43%) patients had sustained an angiographically confirmed arterial or venous injury. Compared with DSA as the gold standard, CTA had a sensitivity and specificity of 72% and 63%, respectively, for identifying PCVI. CTA had a positive predictive value of 61% and negative predictive value of 70%. Seven patients (13%) required immediate endovascular treatment of PCVI; in 3 (43%) of these patients, the injury was not identified on CTA. Twenty-two patients (39%) underwent delayed DSA an average of 25 days after injury; 2 (9%) of these patients were found to harbor new pathological conditions requiring treatment. CONCLUSIONS: In this retrospective analysis of PCVI at two large trauma centers, CTA demonstrated low sensitivity, specificity, and positive and negative predictive values for the diagnosis of PCVI. These findings suggest that DSA provides better accuracy than CTA in the diagnosis of both immediate and delayed PCVI and should be considered for patients experiencing penetrating head or neck trauma.

Cerebral Intraparenchymal Hemorrhage: A Review.

IMPORTANCE: Although spontaneous intraparenchymal hemorrhage (IPH) accounts for less than 20% of cases of stroke, it continues to be associated with the highest mortality of all forms of stroke and substantial morbidity rates. OBSERVATIONS: Early identification and management of IPH is crucial. Blood pressure control, reversal of associated coagulopathy, care in a dedicated stroke unit, and identification of secondary etiologies are essential to optimizing outcomes. Surgical management of hydrocephalus and space occupying hemorrhage in the posterior fossa are accepted forms of treatment. Modern advances in minimally invasive surgical management of primary, supratentorial IPH are being explored in randomized trials. Hemorrhagic arteriovenous malformations and cavernous malformations are surgically excised if accessible, while hemorrhagic dural arteriovenous fistulas and distal/mycotic aneurysms are often managed with embolization if feasible. CONCLUSIONS AND RELEVANCE: IPH remains a considerable source of neurological morbidity and mortality. Rapid identification, medical management, and neurosurgical management, when indicated, are essential to facilitate recovery. There is ongoing evaluation of minimally invasive approaches for evacuation of primary IPH and evolution of surgical and endovascular techniques in the management of lesions leading to secondary IPH.

Eligibility for Endovascular Trial Enrollment in the 6- to 24-Hour Time Window: Analysis of a Single Comprehensive Stroke Center.

BACKGROUND AND PURPOSE: The results of the DAWN trial (Diffusion-Weighted Imaging or Computerized Tomography Perfusion Assessment With Clinical Mismatch in the Triage of Wake Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) support the benefit of endovascular therapy in patients presenting beyond the 6-hour time window with anterior circulation large vessel occlusions. The impact of these results with respect to additional number of eligible patients in clinical practice remains unknown. METHODS: A retrospective review of ischemic stroke admissions to a single DAWN trial-participating comprehensive stroke center was performed during the DAWN enrollment period (November 2014 to February 2017) to identify patients meeting criteria for DAWN and DEFUSE-3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke-3) eligibility. Patients presenting beyond 6 hours were further investigated to clarify reasons for trial exclusion. RESULTS: Of the 2667 patients with acute ischemic stroke admitted within the study period, 30% (n=792) presented within the 6- to 24-hour time window, and 47% (n=1242) had a National Institutes of Health Stroke Scale ≥6. Further clinical trial-specific selection criteria were applied based on the presence of large vessel occlusion, baseline modified Rankin Scale score, core infarct, and perfusion imaging (when available). There were 45 patients who met all DAWN trial criteria and 47 to 58 patients who would meet DEFUSE-3 trial criteria. Thirty-three percent of DAWN-eligible patients are DEFUSE-3 ineligible. CONCLUSIONS: Of all patients with acute ischemic stroke presenting to a single comprehensive stroke center, 1.7% of patients qualified for DAWN clinical trial enrollment with an additional 0.6% to 1% qualifying for the DEFUSE-3 trial. These data predict an increase in thrombectomy utilization with important implications for comprehensive stroke center resource optimization and stroke systems of care.