Levy, Elad I

Background The Woven EndoBridge (WEB) device represents an innovative solution for cerebral aneurysm occlusion, particularly for challenging wide-neck bifurcation aneurysms. However, factors affecting sustained occlusion remain poorly understood. We utilized machine learning to attempt to identify predictors of favorable long-term outcomes following WEB treatment. Methods In this multicenter retrospective study, we collected patient demographics, aneurysm characteristics, procedural details, and clinical outcomes. The primary endpoint was improvement in occlusion status, defined as maintained Raymond-Roy Occlusion Classification (RROC) grade 1, or improvement from grade 2 to 1, or from grade 3 to either 2 or 1 on final angiographic follow up. The dataset was split into training (75%) and validation (25%) sets. The CatBoost algorithm was selected based on performance metrics, with Shapley Additive exPlanations (SHAP) values calculated to determine feature importance. Furthermore, a multivariable binomial logistic regression model was performed to validate machine learning findings. Results Among 720 aneurysms from 36 hospitals, 84% showed improvement in occlusion at follow up. Both machine learning and multivariable logistic regression identified aneurysm height as the most consistent correlate of nonimprovement (odds ratio (OR) 0.90 per mm, p = 0.022). In the CatBoost model, the highest-ranking features by SHAP included aneurysm height, patient age, treatment acuity, ACom location, WEB-SLS device, bifurcation anatomy, aneurysm multiplicity, baseline modified Rankin Scale, access route, and partial thrombosis. Conclusions Machine-learning and regression analyses identified consistent predictors of occlusion improvement after WEB treatment, with aneurysm height most strongly linked to nonimprovement. These insights may guide patient selection and follow up. Findings require cautious interpretation and external validation in larger cohorts.

Background The Woven EndoBridge (WEB) device is a prevalent treatment for intracranial aneurysms. While many studies have assessed the obliteration rate post-WEB embolization, few have focused on long-term outcomes in partially thrombosed aneurysms. Objective To assess whether partially thrombosed aneurysms are at higher risk of recurrence or retreatment following WEB embolization compared with non-thrombosed aneurysms. Methods We evaluated data from 22 academic institutions, focusing on previously untreated cerebral aneurysms treated with the WEB device. Logistic regression was utilized to analyze factors predicting long-term aneurysm obliteration and retreatment necessity. Results Among 1303 patients, 26 presented with a partially thrombosed aneurysm. In the partially thrombosed group, the mean aneurysm maximal diameter was 10.7±4 mm with a neck ratio of 1.99±1.19 mm, larger than in the control group where the mean aneurysm maximal diameter was 6.81±2.37 mm with a neck ratio of 1.64±0.51 mm (P<0.001 for both maximal diameter and neck ratio). At the final follow-up, partially thrombosed aneurysms treated by the WEB device had a 38.5% retreatment rate, compared with 7.0% for non-thrombosed aneurysms (P<0.001). Among partially thrombosed aneurysms, the Raymond-Roy type IIIa/b occlusion rate was higher (38.5% vs 9.9%, P<0.001). On multivariate analysis, partially thrombosed aneurysms compared with non-thrombosed aneurysms had an increased rate of retreatment (OR 3.64, 95% CI 1.28 to 10.1). Conclusion Partially thrombosed aneurysms are associated with a poorer occlusion rate and a higher rate of retreatment following WEB embolization. For partially thrombosed aneurysms, the WEB device appears suboptimal as a first-line treatment, and therefore alternative techniques should be prioritized.

BACKGROUND: The EXCELLENT registry aimed to evaluate the effectiveness of the EMBOTRAP Revascularization Device in an all-comer population in a real-world setting, with a focus on the composition of retrieved clots. METHODS: EXCELLENT is a prospective, global registry of patients with acute ischemic stroke treated with EMBOTRAP as the first-line mechanical thrombectomy device conducted at 34 sites (25 sites contributing clot) from September 2018 to March 2021, utilizing core imaging and central histology laboratories blinded to clinical data, independent 90-day modified Rankin Scale assessment and Clinical Events Committee. RESULTS: After screening 3799 patients, a total of 997 subjects (mean age, 70.0±14.2 years; 51.8% women; 19.7% non-White) were included. The first-pass modified Treatment in Cerebral Infarction (mTICI) ≥2b rate was 64.5% (623/966), first-pass mTICI ≥2c was 39.1% (378/966), and final mTICI ≥2b was 94.5% (931/985). A total of 427/912 (46.8%) patients achieved a 90-day modified Rankin Scale of 0 to 2 or ≤baseline. Embolization to a new territory occurred in 0.2% (2/984), and symptomatic intracranial hemorrhage at 24 hours in 1.6% (16/997). The 90-day mortality was 19.1% (175/918). Device- and/or procedure-related serious adverse events occurred in 5.9% (54/912) through 90 days. The mean RBC percentage of retrieved clots was 45.62±21.372. Among patients who achieved mTICI ≥2b with the first pass, 15.7% (52/331) and 9.7% (32/331), respectively, had RBC-poor (<25%) and RBC-rich (>75%) clots. Patients with no clot retrieved in any procedural pass had a lower percentage of hyperdense or susceptibility vessel sign on baseline imaging (58.9% versus 74.7%; P <0.001), pointing to a potential preprocedure indicator of challenging clot. CONCLUSIONS: The EXCELLENT registry informs real-world practices in mechanical thrombectomy and sheds light on the range of clots effectively retrieved by current technology. This is the first report of detailed patient characteristics where mechanical thrombectomy maneuvers failed to remove any clot material. Although the composition of nonretrievable clots cannot be assessed histologically, the results support the notion that no retrieval may be correlated with imaging findings suggesting clots lower in RBC. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03685578.

Abstract Background Flow diversion is a common endovascular treatment for cerebral aneurysms, but studies comparing different types of flow diverters are scarce. Objective To perform a propensity score matched cohort study comparing the Pipeline Embolization Device (PED) and Flow Redirection Intraluminal Device (FRED) for posterior circulation aneurysms. Methods Consecutive aneurysms of the posterior circulation treated at 25 neurovascular centers with either PED or FRED were collected. Propensity score matching was used to control for age, duration of follow-up imaging, adjunctive coiling, and aneurysm location, size, and morphology; previously ruptured aneurysms were excluded. The two devices were compared for the following outcomes: procedural complications, aneurysm occlusion, and functional outcome. Results A total of 375 aneurysms of the posterior circulation were treated in 369 patients. The PED was used in 285 (77.2%) and FRED in 84 (22.8%) procedures. Aneurysms treated with the PED were more commonly fusiform and larger than those treated with FRED. To account for these important differences, propensity score matching was performed resulting in 33 PED and FRED unruptured aneurysm pairs. No differences were found in occlusion status and neurologic thromboembolic or hemorrhagic complications between the two devices. The proportion of patients with favorable functional outcome was higher with FRED (100% vs 87.9%, p=0.04). Conclusion Comparative analysis of PED and FRED for the treatment of unruptured posterior circulation aneurysms did not identify significant differences in aneurysm occlusion or neurologic complications. Variations in functional outcomes warrant additional investigations.