Use of the pRESET LITE thrombectomy device in combined approach for medium vessel occlusions: A multicenter evaluation.

PURPOSE: Our purpose was to assess the efficacy and safety of the pRESET LITE stent retriever (Phenox, Bochum, Germany), designed for medium vessel occlusion (MeVO) in acute ischemic stroke (AIS) patients with a primary MeVO. METHODS: We performed a retrospective analysis of the MAD MT Consortium, an integration of prospectively maintained databases at 37 academic institutions in Europe, North America, and Asia, of AIS patients who underwent mechanical thrombectomy with the pRESET LITE stent retriever for a primary MeVO. We subcategorized occlusions into proximal MeVOs (segments A1, M2, and P1) vs. distal MeVOs/DMVO (segments A2, M3-M4, and P2). We reviewed patient and procedural characteristics, as well as angiographic and clinical outcomes. RESULTS: Between September 2016 and December 2021, 227 patients were included (50% female, median age 78 [65-84] years), of whom 161 (71%) suffered proximal MeVO and 66 (29%) distal MeVO. Using a combined approach in 96% of cases, successful reperfusion of the target vessel (mTICI 2b/2c/3) was attained in 85% of proximal MeVO and 97% of DMVO, with a median of 2 passes (IQR: 1-3) overall. Periprocedural complications rate was 7%. Control CT at day 1 post-MT revealed a hemorrhagic transformation in 63 (39%) patients with proximal MeVO and 24 (36%) patients with DMVO, with ECASS-PH type hemorrhagic transformations occurring in 3 (1%) patients. After 3 months, 58% of all MeVO and 63% of DMVO patients demonstrated a favorable outcome (mRS 0-2). CONCLUSION: Mechanical thrombectomy using the pRESET LITE in a combined approach with an aspiration catheter appears effective for primary medium vessel occlusions across several centers and physicians.

Repeat Flow Diversion for Cerebral Aneurysms Failing Prior Flow Diversion: Safety and Feasibility From Multicenter Experience.

BACKGROUND: Aneurysmal persistence after flow diversion (FD) occurs in 5% to 25% of aneurysms, which may necessitate retreatment. There are limited data on safety/efficacy of repeat FD-a frequently utilized strategy in such cases. METHODS: A series of consecutive patients undergoing FD retreatment from 15 centers were reviewed (2011-2019), with inclusion criteria of repeat FD for the same aneurysm at least 6 months after initial treatment, with minimum of 6 months post-retreatment imaging. The primary outcome was aneurysmal occlusion, and secondary outcome was safety. A multivariable logistic regression model was constructed to identify predictors of incomplete occlusion (90%-99% and <90% occlusion) versus complete occlusion (100%) after retreatment. RESULTS: Ninety-five patients (median age, 57 years; 81% women) harboring 95 aneurysms underwent 198 treatment procedures. Majority of aneurysms were unruptured (87.4%), saccular (74.7%), and located in the internal carotid artery (79%; median size, 9 mm). Median elapsed time between the first and second treatment was 12.2 months. Last available follow-up was at median 12.8 months after retreatment, and median 30.6 months after the initial treatment, showing complete occlusion in 46.2% and near-complete occlusion (90%-99%) in 20.4% of aneurysms. There was no difference in ischemic complications following initial treatment and retreatment (4.2% versus 4.2%; P>0.99). On multivariable regression, fusiform morphology had higher nonocclusion odds after retreatment (odds ratio [OR], 7.2 [95% CI, 1.97-20.8]). Family history of aneurysms was associated with lower odds of nonocclusion (OR, 0.18 [95% CI, 0.04-0.78]). Likewise, positive smoking history was associated with lower odds of nonocclusion (OR, 0.29 [95% CI, 0.1-0.86]). History of hypertension trended toward incomplete occlusion (OR, 3.10 [95% CI, 0.98-6.3]), similar to incorporated branch into aneurysms (OR, 2.78 [95% CI, 0.98-6.8]). CONCLUSIONS: Repeat FD for persistent aneurysms carries a reasonable success/safety profile. Satisfactory occlusion (100% and 90%-99% occlusion) was encountered in two-thirds of patients, with similar complications between the initial and subsequent retreatments. Fusiform morphology was the strongest predictor of retreatment failure.

Multicenter Study for the Treatment of Sidewall versus Bifurcation Intracranial Aneurysms with Use of Woven EndoBridge (WEB).

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.

International controlled study of revascularization and outcomes following COVID-positive mechanical thrombectomy.

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.

Predictors of aneurysm occlusion following treatment with the WEB device: systematic review and case series.

The Woven EndoBridge (WEB) device is becoming increasingly popular for treatment of wide-neck aneurysms. As experience with this device grows, it is important to identify factors associated with occlusion following WEB treatment to guide decision making and screen patients at high risk for recurrence. The aim of this study was to identify factors associated with adequate aneurysm occlusion following WEB device treatment in the neurosurgical literature and in our case series. A systematic review of the present literature was conducted to identify studies related to the prediction of WEB device occlusion. In addition, a retrospective review of our institutional data for patients treated with the WEB device was performed. Demographics, aneurysm characteristics, procedural variables, and 6-month follow-up angiographic outcomes were recorded. Seven articles totaling 450 patients with 456 aneurysms fit our criteria. Factors in the literature associated with inadequate occlusion included larger size, increased neck width, partial intrasaccular thrombosis, irregular shape, and tobacco use. Our retrospective review identified 43 patients with 45 aneurysms. A total of 91.1% of our patients achieved adequate occlusion at a mean follow-up time of 7.32 months. Increasing degree of contrast stasis after WEB placement on the post-deployment angiogram was significantly associated with adequate occlusion on follow-up angiogram (p = 0.005) and with Raymond-Roy classification (p = 0.048), but not with retreatment (p = 0.617). In our systematic review and case series totaling 450 patients with 456 aneurysms, contrast stasis on post-deployment angiogram was identified as a predictor of adequate aneurysm occlusion, while morphological characteristics such as larger size and wide neck negatively impact occlusion.

Mechanical Thrombectomy in Patients Presenting with NIHSS Score <6: A Safety and Efficacy Analysis.

BACKGROUND AND OBJECTIVES: Groundbreaking trials have shown the tremendous efficacy of mechanical thrombectomy for large vessel occlusions. Currently, mechanical thrombectomy is limited to patients with NIHSS scores ≥6. We investigated the feasibility and safety of MT in patients presenting with NIHSS scores <6. MATERIALS AND METHODS: A retrospective review of patient who presented with acute ischemic stroke due to large vessel occlusion with an NIHSS score <6 between 2015 - 2021. The patients were then divided into two groups: those who received mechanical thrombectomy and those who did not. RESULTS: Among 83 patients, 41 received a mechanical thrombectomy while 42 received medical treatment only. The mean age in the mechanical thrombectomy group was 66 years versus 60 years in the medical group (p = 0.06). Risk factors for stroke did not differ significantly between both groups. 14 patients (34.1%) in the mechanical thrombectomy group and 20 (47.6%) in the medical group received tissue plasminogen activator. No significant difference in clinical improvement (NIHSS) at discharge (p=0.85) or the mRS score at 90 days (p = 0.15) was noted. Mechanical thrombectomy was associated with smaller infarct size (p=0.04) and decreased mortality (p=0.03). CONCLUSIONS: Mechanical thrombectomy is safe and effective for patients who present with large vessel occlusions and low initial NIHSS scores. Therefore, the decision to offer the patient mechanical thrombectomy or not should not be decided by NIHSS score alone. Rather, the decision should be multifactorial with the aim of maximizing the patients' outcomes.

A comparative study of transradial versus transfemoral approach for flow diversion.

PURPOSE: Data in neurointerventional literature is extremely limited regarding the safety and efficacy of flow diversion using transradial access (TRA). We aim to demonstrate the safety and efficacy of intracranial aneurysm treatment with the Pipeline Embolization Device (PED) using TRA compared to transfemoral access (TFA). METHODS: We conducted a retrospective analysis of a prospectively maintained database and identified 79 consecutive patients who underwent neuroendovascular embolization for cerebral aneurysms using the PED from April 2018 through October 2019. Patients were divided into 2 groups: TRA (32 patients) and TFA (47 patients). A comparative analysis was performed between the two groups. RESULTS: There was no significant difference in postoperative intracranial hemorrhage (p>.99), symptomatic ischemic stroke (p=.512), access site complications (p=.268), or other complications (p=.512). However, there was a significant increase in overall complications (14.9% vs. 0.0%, p=.038) and procedure duration (71.4 min ± 31.2 vs. 58.5 ± 20.3, p=.018) in the TFA group. There was no significant difference in complete occlusion at latest follow-up (19/25, 76.0% vs. 35/40, 87.5%; p=.311), 6-month follow-up (17/23, 73.9% vs. 33/38, 86.8%; p=.303), or 12-month follow-up (8/8, 100.0% vs. 5/6, 83.3%; p=.429). There was also no significant difference in rate of retreatment (p>.99), morbidity (p=.512), mortality (p>.99), latest follow-up (p=.985), or loss of follow-up (p=.298). CONCLUSIONS: The feasibility and efficacy of flow diversion with the PED via TRA for the treatment of intracranial aneurysms is comparable to TFA. Widespread adoption of this approach may be facilitated by improvements in device navigation and manipulation via radial-specific engineering.

Low diagnostic yield in follow-up MR imaging in patients with spontaneous intracerebral hemorrhage with a negative initial MRI.

PURPOSE: Follow-up MRI/MRA is historically obtained as outpatient when patients with a spontaneous intracerebral hemorrhage (ICH) have an initial MRI/MRA that is negative for an underlying structural lesion. However, the utility of repeating MR imaging in a delayed fashion remains uncertain. METHODS: We retrospectively reviewed 396 patients with spontaneous ICH admitted at our institution between 2015 and 2017 and selected those whose initial MRI/MRA was negative for an underlying structural lesion and those who underwent follow-up MR imaging in a delayed fashion. RESULTS: A total of 113 patients met the study criteria. The average age of those with negative follow-up MRI/MRA was 65.0 ± 12.6 (IQR: 55.0-74.0) years old. None of the 113 patients with a negative inpatient MRI/MRA had an underlying structural lesion on follow-up MRI/MRA (0%, 95% CI 0.0-0.032, p < 0.001). The mean time of the follow-up imaging from the initial study was 105.7 days (median: 62 days; IQR: 42.5-100.5). Of the 113, 83 (73.5%) underwent follow-up MRI with and without gadolinium, while 30 (26.5%) patients did not receive gadolinium. CONCLUSION: Delayed follow-up MRI in patients with a negative initial MRI/MRA for workup of spontaneous ICH was not diagnostic in any of the patients included in the study. Our study suggests that a routine follow-up MRI for this patient population is not necessary.

Adoption of the Transradial Approach for Neurointerventions: A National Survey of Current Practitioners.

OBJECTIVES: The transradial approach (TRA) is technically feasible for both diagnostic and therapeutic neurointerventions. It improves patient comfort and is not associated with increased procedural complications when compared to the transfemoral approach (TFA). To date, no studies have looked at barriers to adoption of TRA in the neurointerventionalist community. This study aims to obtain neurointerventionalist perspectives on their adoption of TRA. MATERIALS AND METHODS: Online survey distributed to neurointerventionalists. RESULTS: A total of 55 neurointerventionalists, 52 of whom utilized TRA, responded to our survey. Overall, participants were not concerned about TRA's technical feasibility for diagnostic or therapeutic neurointerventions or about procedural complications. Most of our cohort adopted TRA due to its increased patient comfort and to reduce access site complications. In-institution interventionalists were strongly perceived to be the most effective method of teaching TRA when compared to other methods. Catheters and equipment issues were reported by about 30% of our cohort as a barrier to TRA adoption. CONCLUSIONS: The neurointerventionalist community largely perceives TRA to be technically feasible and was not concerned about its procedural complications. In-person institutionalists are strongly perceived to be the most effective method of teaching the approach. A significant barrier to adoption seems to be related to catheters and equipment issues.

A Machine Learning Approach to First Pass Reperfusion in Mechanical Thrombectomy: Prediction and Feature Analysis.

INTRODUCTION: Novel machine learning (ML) methods are being investigated across medicine for their predictive capabilities while boasting increased adaptability and generalizability. In our study, we compare logistic regression with machine learning for feature importance analysis and prediction in first-pass reperfusion. METHODS: We retrospectively identified cases of ischemic stroke treated with mechanical thrombectomy (MT) at our institution from 2012-2018. Significant variables used in predictive modeling were demographic characteristics, medical history, admission NIHSS, and stroke characteristics. Outcome was binarized TICI on first pass (0-2a vs 2b-3). Shapley feature importance plots were used to identify variables that strongly affected outcomes. RESULTS: Accuracy for the Random Forest and SVM models were 67.1% compared to 65.8% for the logistic regression model. Brier score was lower for the Random Forest model (0.329 vs 0.342) indicating better predictive capability. Other supervised learning models performed worse than the logistic regression model, with accuracy of 56.2% for Naïve Bayes and 61.6% for XGBoost. Shapley plots for the Random Forest model showed use of aspiration, hyperlipidemia, hypertension, use of stent retriever, and time between symptom onset and catheterization as the top five predictors of first pass reperfusion. CONCLUSION: Use of machine learning models, such as Random Forest, for the study of MT outcomes, is more accurate than logistic regression for our dataset, and identifies new factors that contribute to achieving first pass reperfusion. The benefits of machine learning, such as improved predictive capabilities, integration of new data, and generalizability, establish ML as the preferred model for studying outcomes in stroke.

Comparison of Anesthetic Agents Dexmedetomidine and Midazolam During Mechanical Thrombectomy.

OBJECTIVES: The ideal anesthetic for mechanical thrombectomy (MT) is a subject of debate. Recent studies have supported the use of monitored anesthesia care (MAC), but few have attempted to compare MAC neuroanesthetics. Our study directly compares midazolam and dexmedetomidine (DEX) on blood pressure control during thrombectomy and functional outcomes at discharge. MATERIALS AND METHODS: We performed a retrospective review of an MT database, which consisted of 612 patients admitted between 2010-2019 to our tertiary stroke center. 193 patients who received either midazolam or DEX for MAC induction were identified. Primary and secondary outcomes were >20% maximum decrease in mean arterial pressure during MT and functional independence respectively. RESULTS: 146 patients were administered midazolam, while 47 were administered DEX. Decrease in blood pressure (BP) during MT was associated with lower rates of functional independence at last follow-up (p=0.034). When compared to midazolam, DEX had significantly higher rates of intraprocedural decrease in MAP at the following cut-offs: >20% (p<0.001), >30% (p=0.001), and >40% (p=0.006). On multivariate analysis, DEX was an independent predictor of >20% MAP decrease (OR 7.042, p<0.001). At time of discharge, NIHSS scores and functional independence (mRS 0-2) were statistically similar between DEX and midazolam. Functional independence at last known follow-up was statistically similar between DEX and midazolam (p = 0.643). CONCLUSIONS: Use of DEX during MT appears to be associated with increased blood pressure volatility when compared to midazolam. Further investigation is needed to determine the impact of MAC agents on functional independence.

Characteristics and Outcomes in Patients With COVID-19 and Acute Ischemic Stroke: The Global COVID-19 Stroke Registry.

Recent case-series of small size implied a pathophysiological association between coronavirus disease 2019 (COVID-19) and severe large-vessel acute ischemic stroke. Given that severe strokes are typically associated with poor prognosis and can be very efficiently treated with recanalization techniques, confirmation of this putative association is urgently warranted in a large representative patient cohort to alert stroke clinicians, and inform pre- and in-hospital acute stroke patient pathways. We pooled all consecutive patients hospitalized with laboratory-confirmed COVID-19 and acute ischemic stroke in 28 sites from 16 countries. To assess whether stroke severity and outcomes (assessed at discharge or at the latest assessment for those patients still hospitalized) in patients with acute ischemic stroke are different between patients with COVID-19 and non-COVID-19, we performed 1:1 propensity score matching analyses of our COVID-19 patients with non-COVID-19 patients registered in the Acute Stroke Registry and Analysis of Lausanne Registry between 2003 and 2019. Between January 27, 2020, and May 19, 2020, 174 patients (median age 71.2 years; 37.9% females) with COVID-19 and acute ischemic stroke were hospitalized (median of 12 patients per site). The median National Institutes of Health Stroke Scale was 10 (interquartile range [IQR], 4-18). In the 1:1 matched sample of 336 patients with COVID-19 and non-COVID-19, the median National Institutes of Health Stroke Scale was higher in patients with COVID-19 (10 [IQR, 4-18] versus 6 [IQR, 3-14]), P=0.03; (odds ratio, 1.69 [95% CI, 1.08-2.65] for higher National Institutes of Health Stroke Scale score). There were 48 (27.6%) deaths, of which 22 were attributed to COVID-19 and 26 to stroke. Among 96 survivors with available information about disability status, 49 (51%) had severe disability at discharge. In the propensity score-matched population (n=330), patients with COVID-19 had higher risk for severe disability (median mRS 4 [IQR, 2-6] versus 2 [IQR, 1-4], P<0.001) and death (odds ratio, 4.3 [95% CI, 2.22-8.30]) compared with patients without COVID-19. Our findings suggest that COVID-19 associated ischemic strokes are more severe with worse functional outcome and higher mortality than non-COVID-19 ischemic strokes.

Radial Artery Catheterization for Neuroendovascular Procedures.

Background and Purpose- Radial artery catheterization is an alternate route of access that has started to gain more widespread use for neuroendovascular procedures, and there have been few studies that describe its safety and efficacy. We present our institution's experience in performing neuroendovascular interventions via a transradial approach, with excellent clinical outcomes and patient satisfaction measures. Methods- We conducted a retrospective analysis and identified 223 patients who underwent 233 consecutive neuroendovascular interventions via radial artery access at our institution. The incidence of perioperative and postprocedural complications was investigated. We identified a subset of 98 patients who have undergone both transradial and transfemoral cerebral angiograms and compared clinical outcomes and patient satisfaction measures between the 2 groups. Results- The overall incidence of complications was low across all procedures performed via transradial access. Peri-procedurally, only 2 patients had symptomatic radial artery spasm, and there were no instances of iatrogenic complications (vessel dissection, stroke, and hemorrhage). In 10 cases (4.3%), the intended procedure could not be completed via a transradial approach, and, thus, femoral artery access had to be pursued instead. Ten patients complained of minor postprocedural complications, although none required therapeutic intervention. The mean procedure time was shorter for diagnostic angiograms performed via transradial versus transfemoral access (18.8±15.8 versus 39.5±31.1 minutes; P=0.025). Patients overall reported shorter recovery times with transradial access, and the majority of patients (94%) would elect to have subsequent procedures performed via this route. Conclusions- Radial artery catheterization is a safe and durable alternative to perform a wide range of neuroendovascular procedures, with a low rate of complications. On the whole, patients prefer transradial compared with transfemoral access.

Predictors of occlusion, long-term outcomes, and safety in a cohort of 674 aneurysms treated with the Pipeline embolization device.

OBJECTIVE: By providing a more physiological approach to the treatment of intracranial aneurysms, the Pipeline embolization device (PED) has revolutionized the endovascular treatment of aneurysms. Although there are many flow diverters on the market, the authors report their experience with the PED, the first flow diverter to be approved by the Food and Drug Administration. They aimed to assess the efficacy and safety of PED flow diversion for the treatment of a wide range of aneurysms, as well as to look at factors affecting occlusion. METHODS: This is a retrospective study of a prospectively maintained database of patients treated with the PED between January 2011 and December 2019. Charts were reviewed for patient, aneurysm, and procedure characteristics. The primary outcomes of interest were complication rates, occlusion outcomes (O'Kelly-Marotta grading scale), and functional outcomes (modified Rankin Scale [mRS]). Secondary outcomes included predictors of incomplete occlusion at 6 and 24 months of follow-up. RESULTS: The study cohort included 581 patients with 674 aneurysms. Most aneurysms (90.5%) were in the anterior circulation and had a saccular morphology (85.6%). Additionally, 638 aneurysms (94.7%) were unruptured, whereas 36 (5.3%) were acutely ruptured. The largest mean aneurysm diameter was 8.3 ± 6.1 mm. Complications occurred at a rate of 5.5% (n = 32). The complete occlusion rate was 89.3% at 24 months' follow-up, and 94.8% of patients had a favorable neurological outcome (mRS score 0-2) at the last follow-up. On multivariate analysis, predictors of incomplete aneurysm occlusion at 6 months were hypertension (OR 1.7, p = 0.03), previous aneurysm treatment (OR 2.4, p = 0.001), and increasing aneurysm neck diameter (OR 1.2, p = 0.02), whereas a saccular morphology was protective (OR 0.5, p = 0.05). Predictors of incomplete occlusion at 24 months were increasing aneurysm neck diameter (OR 1.2, p = 0.01) and previous aneurysm treatment (OR 2.3, p = 0.01). CONCLUSIONS: The study findings are corroborated by those of previous studies and trials. The complete occlusion rate was 89.3% at 24 months' follow-up, with 94.8% of patients having favorable functional outcomes (mRS score 0-2). Aneurysm treatment before PED deployment and an increasing aneurysm neck diameter increase the risk of incomplete occlusion at 6 and 24 months.

First pass effect as an independent predictor of functional outcomes in medium vessel occlusions: An analysis of an international multicenter study.

INTRODUCTION: First pass effect (FPE), achievement of complete recanalization (mTICI 2c/3) with a single pass, is a significant predictor of favorable outcomes for endovascular treatment (EVT) in large vessel occlusion stroke (LVO). However, data concerning the impact on functional outcomes and predictors of FPE in medium vessel occlusions (MeVO) are scarce. PATIENTS AND METHODS: We conducted an international retrospective study on MeVO cases. Multivariable logistic modeling was used to establish independent predictors of FPE. Clinical and safety outcomes were compared between the two study groups (FPE vs non-FPE) using logistic regression models. Good outcome was defined as modified Rankin Scale 0-2 at 3 months. RESULTS: Eight hundred thirty-six patients with a final mTICI ⩾ 2b were included in this analysis. FPE was observed in 302 patients (36.1%). In multivariable analysis, hypertension (aOR 1.55, 95% CI 1.10-2.20) and lower baseline NIHSS score (aOR 0.95, 95% CI 0.93-0.97) were independently associated with an FPE. Good outcomes were more common in the FPE versus non-FPE group (72.8% vs 52.8%), and FPE was independently associated with favorable outcome (aOR 2.20, 95% CI 1.59-3.05). 90-day mortality and intracranial hemorrhage (ICH) were significantly lower in the FPE group, 0.43 (95% CI, 0.25-0.72) and 0.55 (95% CI, 0.39-0.77), respectively. CONCLUSION: Over 2/3 of patients with MeVOs and FPE in our cohort had a favorable outcome at 90 days. FPE is independently associated with favorable outcomes, it may reduce the risk of any intracranial hemorrhage, and 3-month mortality.

Multicenter evaluation of mechanical thrombectomy for distal medium vessel occlusions with National Institute of Health Stroke Scale Scores ≥ 6 and ≤ 6.

BACKGROUND: While mechanical thrombectomy is considered standard of care for large vessel occlusions, scientific evidence to support treatment for distal and medium vessel occlusions remains scarce. PURPOSE: To evaluate feasibility, safety, and outcomes in patients with low National Institute of Health Stroke Scale scores undergoing mechanical thrombectomy for treatment of distal medium vessel occlusions. MATERIALS AND METHODS: Retrospective data review and analysis of prospectively maintained databases at 41 academic centers in North America, Asia, and Europe between January 2017 and January 2022. Characteristics and outcomes were compared between groups with low stroke scale score (≤ 6) versus and higher stroke scale scores (> 6). Propensity score matching using the optimal pair matching method and 1:1 ratio was performed. RESULTS: Data were collected on a total of 1068 patients. After propensity score matching, there were a total of 676 patients included in the final analysis, with 338 patients in each group. High successful reperfusion rates were seen in both groups, 90.2% in ≤ 6 and 88.7% in the > 6 stroke scale groups. The frequency of excellent and good functional outcome was seen more common in low versus higher stroke scale score patients (64.5% and 81.1% versus 39.3% and 58.6%, respectively). The 90-day mortality rate observed in the ≤ 6 stroke scale group was 5.3% versus 13.3% in the > 6 stroke scale group. CONCLUSION: Mechanical thrombectomy in distal and medium vessel occlusions, specifically in patients with low stroke scale scores is feasible, though it may not necessarily improve outcomes over IVT.

Predicting incomplete occlusion of intracranial aneurysms treated with flow diverters using machine learning models.

OBJECTIVE: Intracranial saccular aneurysms are vascular malformations responsible for 80% of nontraumatic brain hemorrhage. Recently, flow diverters have been used as a less invasive therapeutic alternative for surgery. However, they fail to achieve complete occlusion after 6 months in 25% of cases. In this study, the authors built a tool, using machine learning (ML), to predict the aneurysm occlusion outcome 6 months after treatment with flow diverters. METHODS: A total of 667 aneurysms in 616 patients treated with the Pipeline embolization device at a tertiary referral center between January 2011 and December 2017 were included. To build the predictive tool, two experiments were conducted. In the first experiment, six ML algorithms (support vector machine [SVM], decision tree, random forest [RF], k-nearest neighbor, XGBoost, and CatBoost) were trained using 26 features related to patient risk factors and aneurysm morphological characteristics, and the results were compared with logistic regression (LR) modeling. In the second experiment, the models were trained using the top 10 features extracted by Shapley additive explanation (SHAP) analysis performed on the RF model. RESULTS: The results showed that the authors' tool can better predict the occlusion outcome than LR (accuracy of 89% for the SVM model vs 62% for the LR model), even when trained using a subset of the features (83% accuracy). SHAP analysis revealed that age, hypertension, smoking status, branch vessel involvement, aneurysm neck, and larger diameter dimensions were among the most important features contributing to accurate predictions. CONCLUSIONS: In this study, an ML-based tool was developed that successfully predicts outcome in intracranial aneurysms treated with flow diversion, thus helping neurosurgeons to practice a more refined approach and patient-tailored medicine.

Endovascular Embolization for Epistaxis: A Single Center Experience and Meta-Analysis.

The optimal treatment for intractable epistaxis is still controversial. Various studies have demonstrated high success rates and low complication rates for endovascular embolization. Herein, the authors report an institutional experience and meta-analysis in terms of efficacy and safety of endovascular embolization of intractable epistaxis. This was a retrospective observational study of 35 patients with epistaxis who underwent 40 embolization procedures between 2010 and 2023. The primary outcome was immediate success defined by immediate cessation of epistaxis at the end of the procedure. Immediate success was achieved in most of the procedures (39, 97.5%). During follow-up, three (7.5%) patients experienced a rebleed. Forty-one studies from 3595 articles were identified for inclusion in the meta-analysis and comprised 1632 patients. The mean pooled age was 57.5 years (95% CI: 57.2-57.8) and most patients were males (mean: 70.4, 95% CI: 69.8-71.0). Immediate success was achieved at a pooled mean of 90.9% (95% CI: 90.4-91.4) and rebleeding was observed at a pooled mean of 17% (95% CI: 16.5-17.5). In conclusion, endovascular embolization proved to be both safe and effective in treating intractable epistaxis carrying a low risk of post-operative stroke.

Comparing treatment outcomes of various intracranial bifurcation aneurysms locations using the Woven EndoBridge (WEB) device.

BACKGROUND: The Woven EndoBridge (WEB) device has Food and Drug Administration approval for treatment of wide-necked intracranial bifurcation aneurysms. The WEB device has been shown to result in adequate occlusion in bifurcation aneurysms overall, but its usefulness in the individual bifurcation locations has been evaluated separately only in few case series, which were limited by small sample sizes. OBJECTIVE: To compare angiographic and clinical outcomes after treatment of bifurcation aneurysms at various locations, including anterior communicating artery (AComA), anterior cerebral artery (ACA) bifurcation distal to AComA, basilar tip, internal carotid artery (ICA) bifurcation, and middle cerebral artery (MCA) bifurcation aneurysms using the WEB device. METHODS: A retrospective cohort analysis was conducted at 22 academic institutions worldwide to compare treatment outcomes of patients with intracranial bifurcation aneurysms using the WEB device. Data include patient and aneurysm characteristics, procedural details, angiographic and functional outcomes, and complications. RESULTS: A total of 572 aneurysms were included. MCA (36%), AComA (35.7%), and basilar tip (18.9%) aneurysms were most common. The rate of adequate aneurysm occlusion was significantly higher for basilar tip (91.6%) and ICA bifurcation (96.7%) aneurysms and lower for ACA bifurcation (71.4%) and AComA (80.6%) aneurysms (p=0.04). CONCLUSION: To our knowledge, this is the most extensive study to date that compares the treatment of different intracranial bifurcation aneurysms using the WEB device. Basilar tip and ICA bifurcation aneurysms showed significantly higher rates of aneurysm occlusion than other locations.