The Influence of Coagulopathy on Radiographic and Clinical Outcomes in Patients Undergoing Middle Meningeal Artery Embolization as Standalone Treatment for Non-acute Subdural Hematomas.

Middle meningeal artery embolization (MMAE) is emerging as a safe and effective standalone intervention for non-acute subdural hematomas (NASHs); however, the risk of hematoma recurrence after MMAE in coagulopathic patients is unclear. To characterize the impact of coagulopathy on treatment outcomes, we analyzed a multi-institutional database of patients who underwent standalone MMAE as treatment for NASH. We classified 537 patients who underwent MMAE as a standalone intervention between 2019 and 2023 by coagulopathy status. Coagulopathy was defined as use of anticoagulation/antiplatelet agents or pre-operative thrombocytopenia (platelets <100,000/µL). Demographics, pre-procedural characteristics, in-hospital course, and patient outcomes were collected. Thrombocytopenia, aspirin use, antiplatelet agent use, and anticoagulant use were assessed using univariate and multivariate analyses to identify any characteristics associated with the need for rescue surgical intervention, mortality, adverse events, and modified Rankin Scale score at 90-day follow-up. Propensity score-matched cohorts by coagulopathy status with matching covariates adjusting for risk factors implicated in surgical recurrence were evaluated by univariate and multivariate analyses. Minimal differences in pre-operative characteristics between patients with and those without coagulopathy were observed. On unmatched and matched analyses, patients with coagulopathy had higher rates of requiring subsequent surgery than those without (unmatched: 9.9% vs. 4.3%; matched: 12.6% vs. 4.6%; both p < 0.05). On matched multivariable analysis, patients with coagulopathy had an increased odds ratio (OR) of requiring surgical rescue (OR 3.95; 95% confidence interval [CI] 1.68-9.30; p < 0.01). Antiplatelet agent use (ticagrelor, prasugrel, or clopidogrel) was also predictive of surgical rescue (OR 4.38; 95% CI 1.51-12.72; p = 0.01), and patients with thrombocytopenia had significantly increased odds of in-hospital mortality (OR 5.16; 95% CI 2.38-11.20; p < 0.01). There were no differences in follow-up radiographic and other clinical outcomes in patients with and those without coagulopathy. Patients with coagulopathy undergoing standalone MMAE for treatment of NASH may have greater risk of requiring surgical rescue (particularly in patients using antiplatelet agents), and in-hospital mortality (in thrombocytopenic patients).

General Versus Nongeneral Anesthesia for Middle Meningeal Artery Embolization for Chronic Subdural Hematomas: Multicenter Propensity Score Matched Study.

BACKGROUND AND OBJECTIVES: The choice of anesthesia type (general anesthesia [GA] vs nongeneral anesthesia [non-GA]) in middle meningeal artery embolization (MMAE) procedures for chronic subdural hematomas (cSDH) differs between institutions and left to care team discretion given lack of standard guidelines. We compare the outcomes of GA vs non-GA in MMAE. METHODS: Consecutive patients receiving MMAE for cSDH at 14 North American centers (2018-2023) were included. Clinical, cSDH characteristics, and technical/clinical outcomes were compared between the GA/non-GA groups. Using propensity score matching (PSM), patients were matched controlling for age, baseline modified Rankin Scale, concurrent/prior surgery, hematoma thickness/midline shift, and baseline antiplatelet/anticoagulation. The primary end points included surgical rescue and radiographic success rates (≥50% reduction in maximum hematoma thickness with minimum 2 weeks of imaging). Secondary end points included technical feasibility, procedural complications, and functional outcomes. RESULTS: Seven hundred seventy-eight patients (median age 73 years, 73.2% male patients) underwent 956 MMAE procedures, 667 (70.4%) were non-GA and 280 were GA (29.6%). After running 1:3 PSM algorithm, this resulted in 153 and 296 in the GA and non-GA groups, respectively. There were no baseline/procedural differences between the groups except radial access more significantly used in the non-GA group (P = .001). There was no difference between the groups in procedural technical feasibility, complications rate, length of stay, surgical rescue rates, or favorable functional outcome at the last follow-up. Subsequent 1:1 sensitivity PSM retained the same results. Bilateral MMAE procedures were more performed under non-GA group (75.8% vs 67.2%; P = .01); no differences were noted in clinical/radiographic outcomes between bilateral vs unilateral MMAE, except for longer procedure duration in the bilateral group (median 73 minutes [IQR 48.3-100] vs 54 minutes [39-75]; P < .0001). Another PSM analysis comparing GA vs non-GA in patients undergoing stand-alone MMAE retained similar associations. CONCLUSION: We found no significant differences in radiological improvement/clinical outcomes between GA and non-GA for MMAE.

The effect of patient age on the degree of midline shift caused by chronic subdural hematomas: a volumetric analysis.

OBJECTIVE: Chronic subdural hematomas (CSDHs) are the among the most common conditions treated by neurosurgeons. Midline shift (MLS) is used as a radiological marker of CSDH severity and the potential need for urgent surgical evacuation. However, a patient's age may affect the degree of MLS for a given hematoma volume. This study aimed to investigate the correlation between the patient's age and the MLS caused by CSDH. METHODS: The database of patients treated for CSDH was reviewed in a single institution. Patients with unilateral CSDH were included. To measure CSDH volume, the preprocedural head CT scans underwent 3D volumetric reconstruction using the TeraRecon software. The effect of age on MLS after adjusting for CSDH volume was investigated using linear regression analysis. RESULTS: Sixty-nine hematomas in 69 patients were included. The age of patients ranged from 25 to 94 years (mean 71.6 years). Hematoma volume and MLS ranged from 27.8 to 215 mL (mean 99.3 mL) and 0-17 mm (mean 6.5 mm), respectively. On multivariate regression analysis, MLS showed a significant independent negative correlation with age after adjusting for CSDH volume (OR -0.11, 95% CI -0.16 to -0.06; p < 0.001), meaning that for a fixed CSDH volume, with each 10-year increase in age the MLS will reduce by 1.1 mm. Moreover, MLS-to-volume ratio showed a significant negative linear correlation with age (r2 = 0.32; p < 0.001). Ten-milliliter increments in CSDH volume resulted in a 1.09-mm increase in MLS in patients younger than 60 years, which is 2.4-fold higher compared to the 0.46-mm increase in those older than 75 years (p < 0.001). CONCLUSIONS: For a fixed CSDH volume, older age correlates with significantly lower MLS. This could be explained by higher parenchymal compliance in older individuals due to increased brain atrophy, and a larger subdural space. Clinical use of MLS to estimate severity of CSDH and gauge treatment decisions should take the patient's age into account.

Predictors of aneurysmal occlusion following intracranial aneurysms treatment with pipeline embolization device.

PURPOSE: Pipeline embolization device (PED) is thought to induce aneurysmal occlusion through diversion of flow away from the aneurysmal sac with subsequent thrombosis and endothelialization. The impact of different factors especially hypertension (HTN)-a known predisposing factor to hypercoagulability and altered endothelial function-on aneurysmal occlusion after flow diversion has not been studied. We sought to determine predictors of aneurysmal occlusion following PED treatment focusing on impact of blood pressure. METHODS: Database of patients with cerebral aneurysms treated with PED from 2013 to 2019 at our institution was retrospectively reviewed. Patients were defined as hypertensive if (1) they had a documented history of HTN requiring anti-HTN medications or (2) average systolic blood pressure on three measurements was > 130 mmHg. The primary outcome was aneurysm occlusion status at the last imaging follow-up. Multivariable logistic regression model was constructed to assess the effect of HTN on occlusion, controlling for age, smoking, aneurysmal size, fusiform morphology, posterior circulation location, and incorporated branches. RESULTS: A total of 331 aneurysms in 294 patients were identified for this analysis. The mean age was 59 years (79.9% female). Fifty-five percent of the cohort were classified as hypertensive. When controlling for other potential confounders, hypertensive patients trended toward higher odds of achieving complete occlusion compared to non-hypertensive patients (OR = 2.05; 95% CI = 0.99-4.25; p = 0.052). Meanwhile, age (OR = 0.91; 95% CI = 0.88-0.95; p < 0.001) and an incorporated branch into an aneurysm (OR = 0.22; 95% CI = 0.08-0.58; p < 0.002) were associated with decreased odds for complete aneurysmal occlusion. CONCLUSION: Hypertensive patients show a trend toward higher odds of achieving complete occlusion when controlling for potential confounders. The HTN-induced hypercoagulable state, enhanced endothelial activation, and altered extracellular matrix regulation might be the contributing factors. Further research is warranted to explore clinical implications of these findings.

Middle Meningeal Artery Embolization in Adjunction to Surgical Evacuation for Treatment of Subdural Hematomas: A Nationwide Comparison of Outcomes With Isolated Surgical Evacuation.

BACKGROUND AND OBJECTIVES: Surgical evacuation is the standard treatment for chronic subdural hematomas (CSDHs) but is associated with a high risk of recurrence and readmission. Middle meningeal artery embolization (MMAE) is a novel treatment approach which could be performed upfront or in adjunction to surgical evacuation. MMAE studies are limited by small sample sizes. This study aimed to describe and compare outcomes of MMAE in adjunction to surgery with those of surgery alone on a national level. METHODS: The national Vizient Clinical Database was queried by use of a specific validated set of International Classification of Diseases, Tenth Revision codes (October 2018-June 2022). Patients with the diagnosis of nontraumatic CSDH who received MMAE and surgical drainage in the same hospitalization were identified, and their outcomes were compared with isolated surgical drainage. RESULTS: A total of 606 subjects from 156 institutes and 6340 subjects from 369 institutes were included in the MMAE plus surgery (M&S) and surgery groups, respectively. Average length of stay was significantly longer in the M&S group (9.87 vs 7.53 days; P < .01). There was no significant difference in the in-hospital mortality rate (2.8% vs 2.9%), but the complication rate was significantly higher in the M&S group (8.7% vs 5.5%; P < .01). Complications that were significantly more common in the M&S group included aspiration pneumonia, postoperative sepsis, and anesthesia-related. Mean direct costs were significantly higher in the M&S group (28 834 vs 16 292 US dollars; P < .01). The 30-day readmission rate was significantly lower in the M&S group compared with the surgery group (4.2% vs 8.0%; P < .01). CONCLUSION: This analysis of large-scale national data indicates that MMAE performed in adjunction to surgery for treatment of CSDH is associated with higher direct costs, higher complication rates, and longer length of stay but lower readmission rates compared with surgical evacuation alone.

Effect of Chronic Anticoagulation on Outcomes of Endovascular Treatment for Unruptured Intracranial Aneurysms-A Propensity-Matched Multicenter Study.

BACKGROUND AND OBJECTIVES: Endovascular treatment of unruptured intracranial aneurysms (UIAs) in patients receiving anticoagulant medications has not been well studied. Whether long-term anticoagulation (AC) use affects aneurysmal obliteration rates and treatment-related complications is unclear. METHODS: Patients with endovascular treatment for UIA from 4 academic centers were identified and divided into AC and non-AC groups. Periprocedural complications, radiographic and clinical outcomes, and retreatment rates were compared between the 2 groups before and after propensity score matching. RESULTS: The initial cohort consisted of 70 patients in the AC group and 355 in the non-AC group. After one-to-one nearest neighbor propensity matching, 38 pairs of patients were compared for periprocedural complications. The total number of complications were higher in the AC group yet not significant (18.4% vs 5.3%, P = .15). After adding imaging follow-up duration to matched variables, 36 pairs were obtained. There was no significant difference in Raymond-Roy occlusion rate between the 2 groups ( P = .74). However, retreatment rate trended higher in the AC group compared with the non-AC group (22.2% vs 5.6%, P = .09). When clinical follow-up duration was added among matched variables, 26 pairs of cases were obtained for long-term clinical outcomes. There was no significant difference in modified Rankin Scale score between the 2 groups ( P = .61). One-to-many nearest neighbor propensities matched analysis with bigger sample sizes yielded similar results. CONCLUSION: The use of anticoagulants does not affect occlusion rates or long-term outcomes in endovascular treatment of UIAs. Retreatment rates were higher in the AC group; however, this was not statistically significant.

Predictors of extended length of stay related to craniotomy for tumor resection.

Background: Hospital length of stay (LOS) related to craniotomy for tumor resection (CTR) is a marker of neurosurgical quality of care. Limiting LOS benefits both patients and hospitals. This study examined which factors contribute to extended LOS (eLOS) at our academic center. Methods: Retrospective medical record review of 139 consecutive CTRs performed between July 2020 and July 2021. Univariate and multivariable analyses determined which factors were associated with an eLOS (≥8 days). Results: Median LOS was 6 days (IQR 3-9 days). Fifty-one subjects (36.7%) experienced an eLOS. Upon univariate analysis, potentially modifiable factors associated with eLOS included days to occupational therapy (OT), physical therapy (PT), and case management clearance (p < .001); and discharge disposition (p < .001). Multivariable analysis revealed that pre-operative anti-coagulant use (OR 10.74, 95% CI 2.64-43.63, p = .001), Medicare (OR 4.80, 95% CI 1.07-21.52, p = .04), ED admission (OR 26.21, 95% CI 5.17-132.99, p < .001), transfer to another service post-surgery (OR 30.00, 95% CI 1.56-577.35, p = .02), and time to post-operative imaging (OR 2.91, 95% CI 1.27-6.65, p = .01) were associated with eLOS. Extended LOS was not significantly associated with ED visits (p = .45) or unplanned readmissions within 30 days of surgery (p = .35), and both (p = .04; p = .04) were less likely following a short LOS (<5 days). Conclusion: While some factors driving LOS related to CTR are uncontrollable, expedient pre- and post-operative management may reduce LOS without compromising care.

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.

Middle meningeal artery embolization as a perioperative adjunct to surgical evacuation of nonacute subdural hematomas: An multicenter analysis of safety and efficacy.

BACKGROUND: By 2030, nonacute subdural hematomas (NASHs) will likely be the most common cranial neurosurgery pathology. Treatment with surgical evacuation may be necessary, but the recurrence rate after surgery is as high as 30%. Minimally invasive middle meningeal artery embolization (MMAE) during the perioperative period has been posited as an adjunctive treatment to decrease the potential for recurrence after surgical evacuation. We evaluated the safety and efficacy of concurrent MMAE in a multi-institutional cohort. METHODS: Data from 145 patients (median age 73 years) with NASH who underwent surgical evacuation and MMAE in the perioperative period were retrospectively collected from 15 institutions. The primary outcome was the rate of recurrence requiring repeat surgical intervention. We collected clinical, treatment, and radiographic data at initial presentation, after evacuation, and at 90-day follow-up. Outcomes data were also collected. RESULTS: Preoperatively, the median hematoma width was 18 mm, and subdural membranes were present on imaging in 87.3% of patients. At 90-day follow-up, median NASH width was 6 mm, and 51.4% of patients had at least a 50% decrease of NASH size on imaging. Eight percent of treated NASHs had recurrence that required additional surgical intervention. Of patients with a modified Rankin Scale score at last follow-up, 87.2% had the same or improved mRS score. The total all-cause mortality was 6.0%. CONCLUSION: This study provides evidence from a multi-institutional cohort that performing MMAE in the perioperative period as an adjunct to surgical evacuation is a safe and effective means to reduce recurrence in patients with NASHs.

Cost Comparison for Open Surgery versus Middle Meningeal Artery Embolization in Patients with Chronic Subdural Hematomas: A Propensity Score-Matched Analysis.

BACKGROUND: Chronic subdural hematoma (cSDH) can be treated with conventional surgery or middle meningeal artery embolization (MMAE). The cost profiles of open surgery versus MMAE have never been studied. Therefore, we sought to compare the costs of surgical and MMAE treatment of cSDH. METHODS: Patients treated with open surgery (2006-2019) and MMAE (2018-2020) were identified from the institutional database. Propensity score matching analysis was used to assemble a balanced group of subjects. Detailed hospitalization costs in each group were collected and compared. RESULTS: A total of 341 conventionally treated and 52 MMAE cases were identified. After propensity score matching, 33 patients were included in each group, for a total of 66 patients for analysis. Direct procedural cost was significantly greater in the MMAE group compared with the open surgery group ($38,255 ± $11,859 vs. $11,206 ± $7888; P < 0.001). Medication cost also was greater in the MMAE group ($6888 ± $6525 vs. $4291 ± $3547; P = 0.048). No significant difference was found in costs for intensive care unit care, pharmacy, therapy, laboratory values, and the emergency department. Imaging costs and other miscellaneous costs (e.g., wound care, preoperative, and postanesthesia care unit) were greater in the open surgery group (P < 0.05). Total hospitalization cost was not significantly different between the 2 groups ($60,598 ± 61,315 vs. $71,569 ± $37,813 for open surgery and MMAE respectively, P = 0.385). No significant differences in number of follow ups or total costs for follow up were found (P > 0.05). CONCLUSIONS: Open surgery and MMAE offer an overall equivalent cost-profile for cSDH treatment when matching for potential cost confounders. Direct procedural costs are greater in MMAE; however, total hospitalization costs and follow up costs are not significantly different.

Optimal Cost-Effective Screening Strategy for Unruptured Intracranial Aneurysms in Female Smokers.

BACKGROUND: The prevalence of intracranial aneurysms among female cigarette smokers was shown to be high in previous studies, yet the cost-effectiveness of screening them has never been explored. OBJECTIVE: To explore the most cost-effective screening strategy for female smokers. METHODS: A decision analytical study was performed with a Markov model to compare different screening strategies with no screening and to explore the most optimal screening strategy for female smokers. Input data for the model were extracted from literature. A single screening at different ages and multiple screening every 15 years, 10 years, 5 years, and 2 years were performed for female smokers in different age ranges. Deterministic and probabilistic sensitivity analyses were performed to evaluate the robustness of the model. Finally, value of information analysis was performed to investigate the value of collecting additional data. RESULTS: Screening female smokers for unruptured intracranial aneurysm is cost-effective. All screening strategies yield extra quality-adjusted life years. Screening at younger age brings more health benefit at lower cost. Frequent screening strategies decrease rupture rate of aneurysms more with higher costs per quality-adjusted life year. Screening after age 70 years and frequent screening (every 2 years) after age 60 years is not optimal. Among all the parameters in the model, collecting additional data on utility of the unscreened population would be most valuable. CONCLUSION: Screening female smokers for intracranial aneurysms once at younger age is most optimal. However, in clinical practice, the duration and intensity of exposure to cigarettes should be taken into consideration.

Radiographic and clinical outcomes with particle or liquid embolic agents for middle meningeal artery embolization of nonacute subdural hematomas.

BACKGROUND: Middle meningeal artery (MMA) embolization is an apparently efficacious minimally invasive treatment for nonacute subdural hematomas (NASHs), but how different embolisates affect outcomes remains unclear. Our objective was to compare radiographic and clinical outcomes after particle or liquid MMA embolization. METHODS: Patients who had MMA embolization for NASH were retrospectively identified from a multi-institution database. The primary radiographic and clinical outcomes-50% NASH thickness reduction and need for surgical retreatment within 90 days, respectively-were compared for liquid and particle embolizations in patients treated 1) without surgical intervention (upfront), 2) after recurrence, or 3) with concomitant surgery (prophylactic). RESULTS: The upfront, recurrent, and prophylactic subgroups included 133, 59, and 16 patients, respectively. The primary radiographic outcome was observed in 61.8%, 61%, and 72.7% of particle-embolized patients and 61.3%, 55.6%, and 20% of liquid-embolized patients, respectively (p = 0.457, 0.819, 0.755). Hazard ratios comparing time to reach radiographic outcome in the particle and liquid groups or upfront, recurrent, andprophylactic timing were 1.31 (95% CI 0.78-2.18; p = 0.310), 1.09 (95% CI 0.52-2.27; p = 0.822), and 1.5 (95% CI 0.14-16.54; p = 0.74), respectively. The primary clinical outcome occurred in 8.0%, 2.4%, and 0% of patients who underwent particle embolization in the upfront, recurrent, and prophylactic groups, respectively, compared with 0%, 5.6%, and 0% who underwent liquid embolization (p = 0.197, 0.521, 1.00). CONCLUSIONS: MMA embolization with particle and liquid embolisates appears to be equally effective in treatment of NASHs as determined by the percentage who reach, and the time to reach, 50% NASH thickness reduction and the incidence of surgical reintervention within 90 days.

North American multicenter experience with the Flow Redirection Endoluminal Device in the treatment of intracranial aneurysms.

OBJECTIVE: Flow diverters have revolutionized the endovascular treatment of intracranial aneurysms. Here, the authors present the first large-scale North American multicenter experience using the Flow Redirection Endoluminal Device (FRED) in the treatment of cerebral aneurysms. METHODS: Consecutive cerebral aneurysms treated with FRED at 7 North American centers between June 2020 and November 2021 were included. Data collected included patient demographic characteristics, aneurysm characteristics, periprocedural and long-term complications, modified Rankin Scale (mRS) scores, and radiological follow-up. RESULTS: In total, 133 aneurysms in 116 patients were treated with 123 FRED deployment procedures and included in this study. One hundred twenty-six aneurysms (94.7%) were unruptured, 117 (88.0%) saccular, and 123 (92.5%) located in anterior circulation. The mean (range) aneurysm maximal width and neck width sizes were 7.2 (1.5-42.5) mm and 4.1 (1.0-15.1) mm, respectively. Successful FRED deployment was achieved in 122 procedures (99.2%). Adjunctive coiling was used in 4 procedures (3.3%). Radiological follow-up was available for 101 aneurysms at a median duration of 7.0 months. At last follow-up, complete occlusion was observed in 55.4% of patients, residual neck in 8.9%, and filling aneurysm in 35.6%; among cases with radiological follow-up duration > 10 months, these values were 21/43 (48.8%), 3/43 (7.0%), and 19/43 (44.2%), respectively. On multivariate regression analysis, age (OR 0.93, p = 0.001) and aneurysm neck size (OR 0.83, p = 0.048) were negatively correlated with odds of complete occlusion at latest follow-up. The retreatment rate was 6/124 (4.8%). The overall complication rate was 31/116 (26.7%). Parent vessel occlusion, covered branch occlusion, and in-stent stenosis were detected in 9/99 (9.1%), 6/63 (9.5%), and 15/99 (15.2%) cases, respectively. The FRED-related, symptomatic, thromboembolic, and hemorrhagic complication rates were 22.4%, 12.9%, 6.9%, and 0.9% respectively. The morbidity rate was 10/116 patients (8.6%). There was 1 death due to massive periprocedural internal carotid artery stroke, and 3.6% of the patients had an mRS score > 2 at the last follow-up (vs 0.9% at baseline). CONCLUSIONS: As the first large-scale North American multicenter FRED experience, this study confirmed the ease of successful FRED deployment but suggested lower efficacy and a higher rate of complications than reported by previous European and South American studies on FRED and other flow-diverting devices. The authors recommend judicious use of this device until future studies can better elucidate the long-term outcomes of FRED treatment.

Middle meningeal artery: An effective pathway for achieving complete obliteration following transarterial Ethylene Vinyl Copolymer (Onyx) embolization of dural arteriovenous fistulas.

OBJECTIVE: Transarterial Onyx embolization is the mainstay of intracranial non-cavernous dural arteriovenous fistulas (dAVFs) treatment. Although the dural arterial supply varies depending on the location, the impact of arterial access on treatment outcomes has remained unclear. The aim of this study was to characterize factors as sociated with complete obliteration following transarterial Onyx embolization, with a special focus on arterial access routes and dAVF location. METHODS: A retrospective analysis of the patients who underwent transarterial Onyx embolization for intracranial dAVFs at two academic institutions was performed. Patients with angiographic follow-up were considered eligible to investigate the impact of the arterial access on achieving complete obliteration. RESULTS: Sixty-eight patients underwent transarterial Onyx embolization of intracranial dAVFs. Complete obliteration was achieved in 65% of all treated patients and in 75% of those with cortical venous reflux. Multivariable analysis identified middle meningeal artery (MMA) access to be a significant independent predictive factor for complete obliteration (OR, 2.32; 95% CI, 1.06-5.06; p=0.034). Subgroup analysis showed that supratentorial and lateral cerebellar convexity dAVFs (OR, 5.72, 95% CI, 1.89-17.33, p=0.002), and Borden type III classification at pre-treatment (OR, 3.13, 95% CI, 1.05- 9.35, p=0.041), were independent predictive factors for complete obliteration following embolization through the MMA. CONCLUSIONS: MMA access is an independent predictive factor for complete obliteration following transarterial Onyx embolization for intracranial non-cavernous dAVFs. It is particularly effective for supratentorial and lateral cerebellar convexity dAVFs and those that are Borden type III.

Middle Meningeal Artery Embolization with Isolated Use of Coils for Treatment of Chronic Subdural Hematomas: A Case Series.

BACKGROUND: Middle meningeal artery embolization (MMAE) is a novel approach for treatment of chronic subdural hematoma (cSDH). Studies comparing different procedural techniques for MMAE are lacking. It is unclear whether isolated use of coils results in suboptimal outcomes compared to when particle embolization is also performed. The objectives of this study are to describe the outcomes of coil-only MMAE and compare them with those of combined use of coils and particles. METHODS: A single-institution retrospective study of cSDH cases treated by MMAE was performed. Clinical outcomes, need for rescue surgery, and changes in hematoma's size were compared between the coil-only and coil + particle groups. RESULTS: Ninety-four hematomas in 78 patients were included. Twelve cases were treated by a coil-only MMAE procedure, often due to presence of dangerous ophthalmic collaterals. No treatment-related complications were observed in the coil-only group. There was no significant difference between the coil-only and coil + particle groups in baseline hematoma axial thickness, volume, midline shift, and duration of follow-up. The rate of need for rescue surgery was similar between the 2 groups (8.3% vs. 8.5%; P = 0.98). Coiling alone resulted in a similar percentage of reduction in cSDH volume (68.3% vs. 71.8%; P = 0.8) and rate of achieving ≥50% reduction in volume (81.8% vs. 76.3%; P = 0.68) compared to coils + particles. CONCLUSIONS: Isolated use of coils for endovascular treatment of cSDHs can be as effective as adjunct use of particle embolization. This method eliminates the risks of cranial nerve and visual complications associated with MMAE, can prevent procedural abortion due to presence of dangerous anastomoses, and reduces the technical complexity of the procedure.

Safety and Efficacy of the Off-Label Use of Pipeline Embolization Device Based on the 2018 Food and Drug Administration-Approved Indications for Intracranial Aneurysms: A Single-Center Retrospective Cohort Study.

BACKGROUND: The pipeline embolization device (PED; ev3/Covidien) has proven safe and effective for treating selected intracranial aneurysms. This device's versatility and popularity have driven increased interest in expanding the latest 2018 Food and Drug Administration-approved indications. OBJECTIVE: To compare "off-label" and "on-label" PED treatment. METHODS: Retrospective analysis of aneurysms treated with PED at a single center from 2013 to 2019. Comparisons were made based on the 2018 Food and Drug Administration-approved indications. RESULTS: A total of 492 treated aneurysms were included (65.2% on-label and 34.8% off-label). Aneurysm complete and near-complete occlusion rate was nonsignificantly lower in the off-label group (80.9% vs 85.7%; P = .19). Off-label treatment had higher rate of poor functional outcomes (modified Rankin Scale [mRS] >2: 10.3% vs 3.5%; P = .002). Although pretreatment mRS was already higher in the off-label group (5.3% vs 0.3%; P < .001) and there were no differences in mRS worsening during follow-up (5.5% vs 2.9%; P = .15). We also found a trend to a higher rate of intracranial hemorrhagic complications in the off-label group (4.7% vs 1.6%; P = .05), but there were no differences in hemorrhages requiring surgical intervention (1.8% vs 1.3%; P = .65). There were no differences in retreatment, thromboembolic complications, and mortality rates. CONCLUSION: Off-label PED treatment may be considered for select aneurysms, which are challenging to treat with other techniques. These cases have similar complete and near-complete occlusion rates compared with on-label cases. There are, however, higher risks of poor functional outcomes despite similar rates of thromboembolic and hemorrhagic complications. This is partly explained by the significantly higher pretreatment mRS score in the off-label group.