Tawk, Rabih G.

Abstract Purpose Although the Woven EndoBridge (WEB) device is increasingly used for the treatment of wide-neck intracranial aneurysms, including in the acute rupture setting, comparative evidence assessing the impact of rupture status remains limited. This study compared angiographic, safety, and clinical outcomes between ruptured and unruptured intracranial aneurysms treated with WEB. Methods We conducted a retrospective analysis of prospectively collected data from the multicenter cohort registry WorldWideWEB, including consecutive adult patients with intracranial aneurysms treated with the WEB. Patients were stratified into groups of ruptured and unruptured aneurysms. Propensity score matching was used to balance baseline characteristics between both groups. Retreatment rate was the primary outcome. Secondary outcomes included mRS, safety events (thromboembolic complications) and angiographic outcomes (periprocedurally and last follow-up). Results Among 1,220 patients, 342 (28.0%) presented with ruptured aneurysms. There was no significant difference in the rate of thromboembolic complications between groups (11.8% vs 5.9%, p = 0.056). At follow-up, adequate occlusion was lower (82.2% vs 93.3%, p < 0.002) and functional outcomes were worse (mRS ≥2 in 34.1% vs 21.9%, p = 0.012) among patients with ruptured aneurysms. Periprocedural adequate occlusion (53.3% vs 53.8%, p>0.9) and retreatment rates (11.8% vs 7.1%, p = 0.14) did not differ between groups after matching. Conclusion Ruptured aneurysms demonstrated expected inferior follow-up functional and angiographic outcomes when compared with unruptured aneurysms, but no difference in retreatment rate and procedural safety. These findings support WEB as a safe and effective treatment option for appropriately selected ruptured intracranial aneurysms in routine clinical practice.

Introduction Although Valsalva maneuvers and strenuous exercise are commonly discouraged in patients with intracranial aneurysms (IAs), the cerebrovascular stress they induce remains poorly characterized. To our knowledge, no prior review has systematically quantified their effects on hemodynamic surrogates of rupture risk. Objective To characterize the acute intracranial hemodynamic effects of strenuous physical activity and Valsalva maneuvers in individuals with and without IAs. Methods We searched PubMed, Embase, Scopus, Web of Science, and Cochrane (February 2025; PROSPERO ID: CRD42025637608) following PRISMA. Eligible studies reported acute changes in SBP, ICP, central venous pressure (CVP), cerebrovascular transmural pressure (CVTMP), middle cerebral artery (MCA) velocity, or CFD‐derived parameters (wall shear stress [WSS], oscillatory shear index [OSI], relative residence time [RRT]) in response to physical exertion or Valsalva. Populations included individuals with or without IAs. Acute neurological symptoms were also reviewed. Results From 2,859 records, 14 studies met inclusion criteria. Eight studies assessed real‐time hemodynamic responses during exercise (91 participants without IAs). Three studies (n=39) showed that resistance exercise increased SBP (mean Δ+21.8 mmHg). Two studies (n=22) showed significant MAP elevation (mean Δ+24.7 mmHg). When combined with a Valsalva maneuver, SBP increased further (mean Δ+26 mmHg; range 20–30). Three studies (n=38) evaluating isolated Valsalva identified significant ICP elevation (mean Δ+15 mmHg; range 5.7–24.3), primarily driven by CVP increases (mean Δ+52.0 mmHg; range 39–56). Breath‐holding during exertion reduced MCA velocity (mean Δ–11.6 cm/s), while continuous ventilation preserved more stable flow. In seven patients, resistance exercise without Valsalva increased CVTMP by 24.5%. In contrast, Valsalva alone raised ICP and CVP without increasing SBP, yielding a CVTMP 11% lower than during exercise alone. These paired observations suggest that Valsalva may transiently offset exercise‐induced transmural stress by raising ICP alongside SBP. However, this effect may be time‐limited and reverse during early recovery—when SBP remains elevated as ICP quickly normalizes—potentially producing a CVTMP rebound above exercise‐only levels. Six CFD studies (11 aneurysms; diameter 6.3–23 mm; 2 ruptured) reported exercise‐related increases in time‐averaged WSS (mean +21.7%, range –4.4% to +50%) and peak WSS (mean +382.3%, range +100% to +628%). Exercise‐induced changes in heart rate and flow pulsatility led to complex redistributions of intra‐aneurysmal WSS, potentially exposing the aneurysmal wall to focal mechanical stress. Conclusion Resistance exercise, especially with breath‐holding, provokes dynamic, time‐sensitive cerebrovascular stress. Valsalva maneuver may transiently lower CVTMP during effort, yet its release with lingering SBP elevation can precipitate delayed transmural pressure surges. The proposed biphasic effect of Valsalva offers a novel conceptual framework for prospective. Our findings underscore the need to define safe, individualized activity thresholds for patients with IAs with patient‐specific validation integrating concurrent physiology and CFD to reduce the risk of IA growth and rupture.

Introduction The risk of aneurysmal subarachnoid hemorrhage (aSAH) during exercise is not well quantified. We assessed temporal clustering of aSAH around physical exertion and around Valsalva‐like activities (defecation or urination). Objectives To estimate the proportion of aSAH cases temporally linked to strenuous activities using reported exposure‐to‐onset window uwing within‐person odds of rupture from case‐crossover studies. Methods We searched PubMed/MEDLINE, Embase, Scopus, Web of Science, and the Cochrane Library from inception through January 2025, and hand‐searched reference lists (PRISMA‐aligned; PROSPERO CRD42025637608). Eligible studies reported the activity at aSAH onset or within a defined pre‐onset window. Exposures were analyzed separately (exertion; defecation/urination). Primary proportional estimates used each study's own exposure‐to‐onset window as reported. To improve comparability, subgroup analysis was performed with only a prespecified subset pooled consecutive case series that explicitly used a ≤2‐hour window between the index activity and aSAH. Within‐person odds ratios (ORs) were abstracted from case‐crossover studies. Risk of bias for observational exposure studies was assessed with ROBINS‐E by two independent reviewers. Results Sixteen studies (published 1980–2022) from 10 countries were included with 5,815 cases of aSAH (mean age 55 years; 60.6% female). Designs comprised 10 case series, 3 case reports, 2 case‐crossover studies, and 1 case‐control study. Activity‐at‐onset was recorded for 4,219/5,815 (72.6%); among these 4,219 patients, mean age was 52.7 years. Using each study's reported window, 308/4,219 (7.3%) aSAH occurred during or within the study‐defined window after physical exertion, and 387/4,219 (9.2%) during/within the window after defecation or urination 695/4,219 (16.5%) were temporally linked to either exposure. In the subset of 10 consecutive case series restricted to ≤2 hours, 275 (5.4%) were linked to exertion and 385 (7.6%) to defecation/urination (combined 660; 13.0%). Study‐specific proportions ranged from 0.8–21.3% for exertion and 2.0–15.4% for defecation/urination. Two case‐crossover studies reported higher within‐person odds of rupture after moderate‐to‐vigorous exertion (OR 2.4–2.7). Temporal clustering of aSAH around exertion or straining was observed in 13–17% of cases, depending on dataset and inclusion criteria. Conclusions Although this relatively high rate of temporal association between aSAH and exercise might suggest an increased risk of aneurysm rupture during strenuous activity, variable definitions and unstated exposure‐to‐onset windows do not permit causal inference. Prospective or registry‐embedded case‐crossover studies using standardized exposure definitions (intensity, duration) and objective exposure capture are needed to refine immediate‐risk estimates and identify patient‐level susceptibility modifiers.

Introduction Chronic internal carotid artery occlusion (CICAO) can result in recurrent ischemic events despite optimal medical therapy. Revascularization may serve as salvage treatment for symptomatic patients who fail medical management. Objective To evaluate the clinical outcomes of endovascular revascularization in patients with symptomatic CICAO. Methods We reviewed consecutive cases of symptomatic CICAO (symptoms ≥4 weeks) undergoing attempted endovascular revascularization between 2011 and 2024. Occlusions were classified as typical (complete) or atypical (pseudo‐occlusion or distal reconstitution via vasa‐vasorum). Outcomes included periprocedural complications (≤24 hours), technical failure, and new ischemic stroke or TIA during follow‐up. Functional status was assessed using the mRS before and after the procedure, with a favorable outcome defined as mRS ≤2. Results Twenty‐five patients were included (21 male; 84%), mean age 67.8 (range: 51‐81). Prior stroke was reported in 18 patients (72%) and TIA in in 13 (52%). Fourteen patients’ occlusion was at the level of the bifurcation (56%), nine at the cervical level (36%), one at the level of the mandible (4%) and one at the level of the common carotid artery (4%). The mean follow‐up duration was 23.1 ± 38.3 months. Dual antiplatelet therapy was used in 15 patients (60%), and single‐agent therapy in eight (32%). Technical treatment success, defined as adequate recanalization of the treated artery, was achieved in 20 (80%) patients, representing 13 of 18 patients from the typical group and all seven from the atypical group. Five patients (20%) failed the endovascular revascularization attempt and were treated with EC‐IC bypass instead (all from typical group). Periprocedural complications occurred in 11 patients (44%), affecting 10 of 18 patients (56%) with typical occlusion and 1 of 7 (14%) with atypical occlusion. During follow‐up, three patients (12%) experienced ischemic stroke and, three (12%) had TIA. Functional status changed in 16 patients (64%), with improvement in 12 and decline in four. Categorically, six patients (24%) transitioned to a favorable outcome (mRS ≤2), while three (12%) shifted to an unfavorable one (two had underlying malignancies). Conclusion Endovascular revascularization offers a salvage option for patients with symptomatic CICAO who fail medical therapy. While the procedure can reduce recurrent ischemia and improve functional outcomes, it carries procedural risks, especially in cases with typical occlusion. Patients with atypical occlusions showed higher success rates and fewer complications, suggesting they may benefit most from this approach. Careful patient selection remains critical, and further studies are needed to refine indications and improve safety.

Introduction Post‐market and multicenter studies report low complete occlusion rates (41‐49%) and higher retreatment rates (13%) following WEB deployment, compared to 3.8% with microsurgical clipping. While retreatment after WEB has been shown to be technically feasible, data on final angiographic outcomes remain limited. We performed a retrospective analysis of prospective databases from 14 cerebrovascular centers in the US to compare the safety and efficacy of retreatment versus continued observation for residual and recurrent aneurysms after initial WEB deployment. Materials/Methods Multinomial logistic regression was used to identify baseline characteristics of untreated and residual/recurrent aneurysms that may act as confounders, which then underwent propensity scored matching (PSM). Results Among 211 patients (125 observed, 86 retreated), retreatment was more common in initially ruptured aneurysms (p<0.001), which showed higher recurrence (p=0.036) and sac‐dominant residuals (p=0.004). These were primarily due to WEB compression on follow‐up (p=0.001), rather than incomplete occlusion with an appropriately sized device (p<0.001). Retreatment was associated with significantly higher rates of complete angiographic occlusion at last follow‐up compared to observation alone (p<0.001), a finding that remained consistent across subgroups defined by initial unruptured status, residual type, and recurrence patterns (all p<0.05). Clipping demonstrated higher, though statistically insignificant, rates of complete occlusion; flow diversion and stent‐assisted coil embolization yielded comparable complete occlusion rates at follow‐up. After propensity score matching, retreatment remained significantly associated with higher rates of complete angiographic occlusion (all p<0.05), with comparable outcomes observed between clipping and various endovascular approaches as above. Conclusion Retreatment improved complete occlusion rates; however, no aneurysmal hemorrhages occurred in either group. Further intervention may be unnecessary when the WEB device—whether compressed or intact (BOSS 0/1)—adequately protects the dome. In cases where WEB compression significantly exposes the aneurysm wall, stent‐assisted coiling or flow diversion can be performed safely and successfully, depending on vascular anatomy and surgeon preference. image image

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: Estimating operative time with low accuracy and precision leads to suboptimal scheduling of available operating rooms (ORs) and waste of healthcare resources. We aimed to develop a predictive machine learning (ML) model for operative time using our institutional data to improve the scheduling of neurosurgical ORs, minimize waste, and maximize resource utilization. Methods: We developed a predictive model using our institution’s multicenter registry, which included diverse neurosurgical cases across three tertiary hospitals. We applied multiple ML techniques, including linear regression, support vector regression, deep neural networks, and extreme gradient boosting regression (XGBR). The best model was combined with the first fit decreasing bin-packing algorithm to create a practical OR scheduling system based on prior data. Results: The XGBR model exhibited the best performance, with lower mean absolute errors (MAEs) (root mean squared error: 52.24, MAE: 37.25) and higher R2 (0.76) values than other models. Implementing this model in a simulated OR scheduling scenario using institutional data, we successfully scheduled 30 random procedures with minimal residual time, such that the model ran out of procedures for the week with 86 and 171 min remaining in the cranial and spinal ORs, respectively, demonstrating potential efficiency gains. The cranial procedures were scheduled over 4 days and spinal procedures over 6 days, optimizing available OR time. Conclusion: Integrating ML models into operative time prediction can significantly improve the accuracy and efficiency of surgical schedules. This approach minimizes wasted OR time and enhances resource allocation, potentially improving patient outcomes and satisfaction by reducing waiting times.

BACKGROUND AND IMPORTANCE: Basilar artery fenestration aneurysms (BAFAs) present significant clinical challenges because of their high rupture risk and complex anatomy. Comprehensive management strategies are required, including thorough vascular assessment and post-treatment surveillance. Integration of complementary analyses such as computational fluid dynamics (CFD) holds promise in facilitating preoperative planning for these intricate lesions. CLINICAL PRESENTATION: A 60-year-old female was diagnosed with a BAFA during evaluation for headaches. Digital subtraction angiography revealed the aneurysm projecting posteriorly with a neck predominantly based on the right limb of the fenestration. After initial treatment with a pipeline embolization device, the aneurysm remained patent, requiring further treatment. A secondary approach with stent-assisted loose-packing coil embolization was then performed, resulting in complete occlusion of the aneurysm. Analysis of pretreatment 3-dimensional rotational angiogram images with CFD provided critical hemodynamic insights. It identified that 38.89% of the aneurysm area was exposed to low wall shear stress (WSS) and 11.5% was exposed to high WSS, indicating a high rupture risk profile with significant areas of both low and high WSS. In addition, low WSS was observed in regions corresponding to daughter sacs, suggesting a higher rupture risk. Streamline analysis indicated increased inflow through the right vertebral artery and the right limb of the fenestration, supporting the initial angiographic impression and guiding the choice of therapeutic strategy. CONCLUSION: This is the first study to analyze the morphology and pretreatment hemodynamics of a BAFA using CFD, illustrating the potential for future development of individualized therapeutic approach–based CFD in complex aneurysms.