Stent Retriever Research Articles

Stent retriever expansion as a corrective maneuver to optimize inadequately deployed flow diverter stents.

As flow diversion (FD) is becoming increasingly important in the endovascular treatment of intracranial aneurysms, the rate of technical complications is also increasing. Inadequate FD implantation may lead to both ischemic complications and decreased treatment efficacy. The aim of this study was to evaluate the efficacy of off-label stent retriever (SR) use in managing technical complications associated with FD implantation. A retrospective analysis of data from patients who underwent FD treatment at two neuroradiology centers was performed. The objective was to identify cases in which the FD was inadequately deployed and SR expansion was performed as a corrective maneuver. The analysis included anatomic characteristics, technical information, angiographic and clinical outcomes, and complications. A total of 35 corrective maneuvers with SR were performed in 25 FD treatments. The corrective maneuvers in all treatments were successful, and no additional devices or therapies were required. No procedural complications or technical difficulties were documented. With the growing role of FDs in neurointerventional treatment, familiarity with corrective maneuvers after technical complications or inadequate implantation is important. The findings in our selected cohort demonstrated that SR expansion is an effective and safe corrective maneuver for incompletely opened FDs.

Vessel deviation during stent retrieval predicts successful recanalization in stent-based mechanical thrombectomy for M2 occlusion.

This study aimed to clarify whether there is a relationship between vessel deviation during stent retrieval and successful recanalization in stent-based mechanical thrombectomy (MT) for M2 occlusion. The video of the MT was reviewed for each of the 25 included patients with M2 occlusion. The vertical distance of vessel deviation at the time of stent retrieval was defined as D, and the diameter of the balloon guide catheter shown on the same screen was defined as B. The D/B ratio was calculated as an index of the vessel deviation. The presence or absence of successful recanalization (thrombolysis in cerebral infarction (TICI) score of 2b/3) was compared based on the D/B ratio and clinical factors. Of the 25 patients, successful recanalization was achieved in 18 (72%). The median D/B ratio with successful recanalization was 0.9, which was significantly lower than that without successful recanalization (2.5, p < 0.001, Mann-Whitney U test). Combined aspiration catheters were used in 24 cases. In nine (36%) cases, the tip of the aspiration catheter was in M2 during stent retrieval. The median D/B ratio with the position of the aspiration catheter tip in M1 or the internal carotid artery was 1.5, which was significantly higher than that with the position in M2 (0, p = 0.003, Mann-Whitney U test). In stent-based MT for M2 occlusion, cases in which successful recanalization was achieved showed less vessel deviation during stent retrieval. To reduce vessel deviation, advancing the combined aspiration catheter up to M2 is useful.

Optimizing stent retrievers for mechanical enhancement and in vitro testing in acute ischemic stroke models

BackgroundAcute ischemic stroke (AIS) remains a major cause of morbidity and mortality worldwide. Mechanical thrombectomy, especially with stent retrievers, offers a promising treatment, particularly for patients ineligible for intravenous tissue plasminogen activator (IV tPA) therapy. This study aimed to develop and evaluate novel stent retriever designs to enhance mechanical properties and vessel compatibility.ResultsWe evaluated four stent designs using finite-element analysis (FEA) to assess their mechanical properties. Based on these evaluations, Stent D emerged as the optimal design due to its superior elasticity and adaptability. Comparative testing of Stent D against commercial stents, Solitaire FR and Trevo XP ProVue, revealed the following metrics: radial forces of 3.77 ± 0.01 N for Solitaire FR, 3.92 ± 0.08 N for Trevo XP ProVue, and 4.10 ± 0.07 N for Stent D; flexibility measurements of 0.38 ± 0.11 N for Solitaire FR, 0.91 ± 0.11 N for Trevo XP ProVue, and 0.59 ± 0.05 N for Stent D; deployment forces of 0.37 ± 0.02 N for Solitaire FR, 0.42 ± 0.04 N for Trevo XP ProVue, and 0.32 ± 0.02 N for Stent D; and recapture forces of 0.38 ± 0.01 N for Solitaire FR, 0.45 ± 0.02 N for Trevo XP ProVue, and 0.35 ± 0.01 N for Stent D. Thrombus retrieval rates were 96.16% for Solitaire FR and 95.51% for Stent D.ConclusionsThese findings demonstrate that Stent D performs comparably to commercial stents, highlighting its effective performance in AIS treatment. Stent D shows promise as a candidate for further clinical evaluation due to its superior mechanical properties and effective thrombus retrieval capabilities.

The safety and efficacy of pRESET stent retriever for treatment of thrombo-embolic stroke; a systematic review and meta-analysis.

The pRESET stent retriever is a self-expanding nitinol stent designed for mechanical thrombectomy in cases of large vessel occlusion during acute ischemic stroke. This systematic review and meta-analysis synthesize the available evidence on the safety and efficacy of the pRESET device. This is a systematic review and meta-analysis study conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The electronic databases of PubMed, Embase, WoS, and Scopus were systematically reviewed from inception to 8 July 2024. A total of eight studies involving 1163 patients were included. The pooled mortality rate was 18% with a 95% CI of [12%, 25%]. The rates of any hemorrhagic complication, parenchymal hemorrhage, and subarachnoid hemorrhage were 22% with a 95% CI of [12%, 36%], 7% with a 95% CI of [4%, 13%], and 10% with a 95% CI of [5%, 17%], respectively. The rate of favorable functional outcome (modified Rankin Scale 0-2) at 90 days was 43% with a 95% CI of [34%, 52%]. Successful recanalization rates were 60% with a 95% CI of [52%, 67%] after the first pass and 90% with a 95% CI of [83%, 95%] after the final pass. Rescue devices were used in 13% with a 95% CI of [7%, 24%] of cases. The pRESET stent retriever demonstrates high recanalization rates and reasonable safety outcomes in patients undergoing mechanical thrombectomy for acute ischemic stroke due to large vessel occlusion. Further randomized trials directly comparing pRESET to other stent retrievers are warranted.

Efficacy and Safety of a Dedicated Device for Cerebral Venous Thrombectomy: A Pilot Randomized Clinical Trial.

Lack of a dedicated thrombectomy device for cerebral venous thrombosis hinders the recanalization ability of endovascular treatment (EVT). Novel NiTi-braided stent retriever (Venous-TD) is a dedicated venous sinus thrombectomy device. This study aims to demonstrate the safety and efficacy of Venous-TD. In this pilot, prospective, randomized, single-blind, parallel-group control, single-center clinical study, patients with cerebral venous thrombosis from Beijing Xuanwu Hospital were included. Randomization was performed to EVT with either the Venous-TD or Angioguard with Sterling balloon (control group). The primary efficacy outcome was the proportion of immediate complete recanalization during EVT. Secondary outcomes included the proportion of functional independence and moderate to severe residential headache at 180 days after EVT. Safety outcomes included peri-procedural complications, all-cause mortality, and symptomatic intracranial hemorrhage after EVT. A total of 61 patients were enrolled and randomized. Thirty-one patients were randomized to the Venous-TD group, and 30 were randomized to the control group. The median (interquartile range) age was 28 (21-45) in the Venous-TD group and 34 (24-43) in the control group. The proportion of patients with a National Institutes of Health Stroke Scale score >8 on admission was 8 (25.8%) in the Venous-TD group and 11 (36.7%) in the control group. During EVT, Venous-TD significantly improved the proportion of complete recanalization compared with Angioguard (23 [76.7%] versus 6 [20.0%]; relative risk, 3.833 [95% CI, 1.825-8.054]). The proportions of long-term functional independence at 180 days in the Venous-TD group and the control group were not significantly different. The proportion of patients with severe residual headache at 180 days in the Venous-TD group was significantly lower than that in the control group (3 [9.7%] versus 10 [35.7%]; relative risk, 0.271 [95% CI, 0.083-0.886]). Safety outcomes showed no statistically significant difference between the 2 groups. This trial indicated that Venous-TD did not increase complications in EVT of cerebral venous thrombosis and can significantly increase the proportion of complete recanalization. A multicenter phase III randomized control trial assessing efficacy and safety of Venous-TD is warranted. URL: https://www.clinicaltrials.gov; Unique identifier: NCT05291585.

Soft partial release of non-aggressive stent retriever technique for very distal arterial occlusion stroke.

Endovascular thrombectomy (EVT) for very distal vessel occlusion (DVO) stroke is increasingly performed but there is insufficient evidence on the efficacy and safety of distal EVT techniques. We hypothesized that the technique of soft partial release of non-aggressive stent retrievers (SPORNS) reduces friction on the perforating vessels during thrombectomy and thereby reduces bleeding complications. Retrospective study including consecutive DVO patients who were treated with the SPORNS technique between 1 January 2022 and 31 December 2022 at two tertiary stroke centers. DVOs were defined as isolated occlusions of the M3 and M4 segments of the middle cerebral artery, occlusions of the A2 and A3 segments of the anterior cerebral artery, and occlusions of the P2 and P3 segments of the posterior cerebral artery or of the superior cerebellar artery. The technique is described in detail and procedural and clinical outcomes are given. Twenty-four patients were treated with the SPORNS technique of whom 22 (92%) had complete or near complete recanalization (eTICI 2c/3). National Institutes of Health Stroke Scale (NIHSS) decreased from a median of nine (IQR 7-13) at admission to three (1-5) at discharge and 18 patients (75%) achieved a good outcome (modified Rankin scale 0-2) at day 90 post-stroke. Two patients (8%) had a small subarachnoid hemorrhage and two patients (8%) had a symptomatic intracerebral hemorrhage on follow-up imaging. For the treatment of very distal arterial occlusions, the SPORNS technique employing a soft partial release of a non-aggressive stent retriever is safe and effective for the thrombectomy of small clots. The technique potentially yields a lower rate of subarachnoid hemorrhages while achieving an excellent rate of complete and first-pass recanalization.

Mechanical thrombectomy failure in anterior and posterior circulation stroke: current results from a high-volume comprehensive center.

Mechanical thrombectomy (MT) is an established therapy for acute ischemic stroke (AIS), but recanalization is not always achieved. Common reasons are inadequate removal at the thrombus site and difficulties with the access route. In order to identify risk factors for MT failure we conducted a retrospective study on a high-volume comprehensive stroke center. Evaluation of 552 thrombectomies (2019-23; anterior and posterior circulation, direct aspiration +/- stent retriever [SR]). MT failures (= modified Thrombolysis in Cerebral Infarction score 0 or 1) were analyzed for age, sex, pre- and post-MT modified Rankin Scale, bridging intravenous thrombolysis (IVT), occlusion site (anterior / posterior circulation, proximal / distal), the Kaesmacher classification and time trend results. MT failure occurred in 56 patients (10.1%; median age 76; 53.6% female). Nineteen (33.9%) patients received IVT (p = 0.326). Logistic regression analysis did not show a significant association of age, sex or occlusion site with MT failure (p = 0.165, p = 0.738, p = 0.838). Distal MT generally demonstrated lower success rates (p < 0.01). According to the Kaesmacher classification SR failure was the most frequent cause of MT failure (category 2B: 48%, p < 0.001). Time trend analysis suggests improving recanalization rates in the further course (4 times in year-on-year comparison; p < 0.01). MT failure occurs in AIS treatment, even in high-volume centers and occurs more frequently in distal occlusions. Improvements in device technology, particularly SR, and ongoing refinements in access route selection offer the prospect of better outcomes in the future.

International practice patterns and perspectives on endovascular therapy for the treatment of cerebral venous thrombosis.

Cerebral venous thrombosis (CVT) accounts for 0.5-1% of all strokes. The role of endovascular therapy (EVT) in the management of CVT remains controversial and variations in practice patterns are not well known. Here, we present a comprehensive, international characterization of practice patterns and perspectives on the use of EVT for CVT.Methods A comprehensive 42-question survey was distributed to stroke clinicians globally from May-October 2023, asking about practice patterns and perspectives on the use of EVT for CVT. The overall response rate was 31% (863 respondents of 2744 invited) across 61 countries. The majority of respondents (74%) supported the use of EVT for CVT in certain clinical situations. Key considerations for decision-making in using EVT favored clinical over radiographic/procedural factors and included worsening level of consciousness (86%) and worsening neurological deficits (76%). In the past three years, 56% of respondents used EVT for the treatment of CVT, with most (49.5%) involved in 2-5 cases. Among interventionalists, significant variability existed in the techniques used for EVT (p<0.001), with aspiration thrombectomy (56%) and stent retriever (51%) being the most used overall. Regionally, interventionalists from China predominately used intra-sinus heparin (56%), while this technique was most commonly ranked as "never indicated" throughout the rest of the world (23%). Post-procedure, low molecular weight heparin was the most used anticoagulant (83%), although North American respondents favored unfractionated heparin (37%), while imaging was primarily split between magnetic resonance (71.8%) and computed tomography (65.9%) arteriography or venography. Our survey reveals significant heterogeneity in approaches to EVT for CVT, and provides a comprehensive characterization of indications, techniques and long-term management used by clinicians internationally. This resource will aid in optimizing patient selection and endovascular treatments for future trials.

A direct aspiration first-pass technique (ADAPT) for acute ischemic stroke thrombectomy: Indications, technique, and emerging devices.

To date, the use of the most suitable first-pass technique for Mechanical Thrombectomy is still debated. In last years, several observational studies have suggested noninferiority or superiority of A Direct Aspiration first-Pass Technique (ADAPT) technique to achieve better reperfusion in comparison to stent retriever. While ASA/AHA 2018 guidelines recommend that patients with AIS should receive Mechanical Thrombectomy with a stent retriever, last European Stroke Organization guidelines report no evidence that stent retriever compared with contact aspiration could improve reperfusion rate. ADAPT is based on aspiration alone as the primary mechanism of thrombectomy and, if initially unsuccessful, then incorporating adjunctive alternatives. ADAPT improvement is also related to last generation of aspiration catheters. The purpose of this review is to report ADAPT principles, technique, efficacy, and safety as first-line treatment for acute ischemic stroke with the latest generation of reperfusion devices.

Stent Retriever AssIsted Lysis Technique with Tirofiban: A Potential Bailout Alternative to Angioplasty and Stenting.

Angioplasty and stent placement have been described as a bailout technique in individuals with failed thrombectomy. We aimed to investigate Stent retriever AssIsted Lysis (SAIL) with tirofiban before angioplasty and stent placement. Patients from 2 comprehensive stroke centers were reviewed (2020-2023). We included patients with failed thrombectomy and/or underlying intracranial stenosis who received SAIL with tirofiban before the intended angioplasty and stent placement. SAIL consisted of deploying a stent retriever through the occluding lesion to create a bypass channel and infuse 10 mL of tirofiban for 10 minutes either intra-arterially or IV. The stent retriever was re-sheathed before retrieval. The primary end points were successful reperfusion (expanded TICI 2b-3) and symptomatic intracerebral hemorrhage. Additional end points included 90-day mRS 0-2 and mortality. After a median of 3 (interquartile range, 2-4) passes, 44 patients received the SAIL bridging protocol with tirofiban, and later they were considered potential candidates for angioplasty and stent placement bailout (43.2%, intra-arterial SAIL). Post-SAIL successful reperfusion was obtained in 79.5%. A notable residual stenosis (>50%) after successful SAIL was observed in 45.7%. No significant differences were detected according to post-SAIL: successful reperfusion (intra-arterial SAIL, 80.0% versus IV-SAIL, 78.9%; P = .932), significant stenosis (33.3% versus 55.0%; P = .203), early symptomatic re-occlusion (0% versus 8.0%; P = .207), or symptomatic intracerebral hemorrhage (5.3% versus 8.0%; P = .721). Rescue angioplasty and stent placement were finally performed in 15 (34.1%) patients (intra-arterial SAIL 21.0% versus IV-SAIL 44%; P = .112). At 90 days, mRS 0-2 (intra-arterial SAIL 50.0% versus IV-SAIL 43.5%; P = .086) and mortality (26.3% versus 12.0%; P = .223) were also similar. In patients with stroke in which angioplasty and stent placement are considered, SAIL with tirofiban, either intra-arterial or IV, seems to safely induce sustained recanalization, offering a potential alternative to definitive angioplasty and stent placement.

Accelerated aspiration with Q™ catheter: An in vitro study.

Thrombectomy in distal, medium vessels is a topic of increasing interest. To date, there are few in vitro studies focused on performance of ≤5F catheters in medium vessels. The purpose of this study is to compare the performance of the 3F, 4F, and 5F MIVI Neuroscience Q Catheters versus Penumbra 3F, 4F, and MicroVention Sofia 5F Catheters. Using in vitro methods, we assessed and compared the following parameters: aspiration flow rates, clot uncorking forces, impulse, and clot ingestion. For flow rate, each aspiration catheter was immersed in a cylindrical container. Flow rate at one second was used to calculate impulse. For clot uncorking force, the force required to disengage a catheter from a simulated clot was recorded. For ingestion, we measured time to ingest soft and medium stiffness synthetic clots. The measured flow rates without a stent retriever for the Q3, Q4, and Q5 catheters were 3.54 ml/s, 5.32 ml/s, and 6.87 ml/s. The measured flow rates without a stent retriever for the 3MAX, 4MAX, and 5F Sofia were 1.46 ml/s, 2.56 ml/s, and 1.73 ml/s. The impulse calculated for one second was 26 mNs for Q5 vs 9 mNs for Sofia 5, 35 mNs for Q4 vs 15 mNs for 4Max< and 35 mNs for Q3 vs 9 mNs for 3Max. The average system ingestion for Q was significantly faster than the competitive catheters. The Q catheters demonstrated higher flow rates, higher uncorking force, and faster complete clot ingestion than competitive catheters.

Iatrogenic emboli during mechanical thrombectomy for acute ischemic stroke: comparison between stent retriever technique and contact aspiration-a retrospective case-control study.

Mechanical thrombectomy (MT) is an effective treatment for acute ischemic stroke from large vessel occlusion (LVO). While embolization to a new territory (ENT) after MT is well-documented, data on embolization in the same distal territory (EDT) are limited. Achieving modified Treatment In Cerebral Infarction (mTICI) 3 reperfusion presents significant clinical benefits over mTICI 2b/2c, necessitating strategies to reduce both ENT and EDT. Previous studies suggest higher rates of EDTs with contact aspiration compared with stentrievers. However, comprehensive comparison studies in clinical practice are scarce. This study compares the rates of overall clot emboli (OCE) between these MT strategies. A retrospective, multicenter observational study was conducted at four university hospitals in France from January 2015 to November 2019. Adult patients (≥18 years) with acute ischemic stroke due to LVO, treated with either contact aspiration (ADAPT, A Direct Aspiration First Pass Technique) or stentrievers, specifically using the Embotrap device to maintain sample homogeneity, were included. Digital subtraction angiography was used for imaging, with two independent, blinded reviewers assessing OCE post-first MT pass. Propensity score full matching and independent sample testing were employed to evaluate OCE after the first MT pass. A significant difference in OCE rates was observed between contact aspiration and stentriever techniques, with the stentriever technique resulting in fewer embolic events compared with ADAPT, based on a propensity score analysis that accounts for key confounding factors. A statistically significant reduction in embolic events was observed with the stentriever technique compared with contact aspiration. These results suggest that the stentriever method may offer a safer profile in terms of embolic risk for LVO interventions, and should be considered over contact aspiration when embolic risk is a primary concern, while also considering individual patient factors.

Investigation of stent retriever removal forces in an experimental model of acute ischemic stroke.

Mechanical thrombectomy becomes more complex when the occlusion occurs in a tortuous cerebral anatomy, increasing the puncture to reperfusion time and the number of attempts for clot removal. Therefore, an understanding of stent retriever performance in these locations is necessary to increase the efficiency and safety of the procedure. An in vitro investigation into the effects of occlusion site tortuosity, blood clot hematocrit, and device geometry was conducted to identify their individual influence on stent retriever removal forces. Embolus analogs were used to create occlusions in a mock circulatory flow loop, and in vitro mechanical thrombectomies were performed in arterial models of increasing tortuosity. The stent retriever removal forces of Solitaire Platinum and EmboTrap II devices were recorded through each geometry with and without embolus analogs present. Similar experiments were also conducted with Solitaire stent retrievers of varying lengths and diameters and 0, 25, and 50% hematocrit embolus analogs. The removal force increased as model tortuosity increased for both the Solitaire Platinum and EmboTrap II stent retriever devices. The average removal forces in the simplest geometry with the Solitaire Platinum and EmboTrap II were 0.24 ± 0.01 N and 0.37 ± 0.02 N, respectively, and increased to 1.2 ± 0.08 N and 1.6 ± 0.17 N, respectively, in the most complex geometry. Slight increases in removal force were found with 0% hematocrit embolus analogs, however, no statistical significance between removal force and EA hematocrit was observed. A comparison between stent retriever removal forces between devices of different diameters also proved to be significant (p < 0.01), while forces between devices of varying lengths were not (p > 0.05). Benchtop mechanical thrombectomies performed with commercial stent retrievers of varying geometry showed that device removal forces increase with increasing model tortuosity, clot hematocrit does not play a significant role in device removal force, and that a stent retriever's diameter has a greater impact on removal forces compared to its length. These results provide an improved understanding of the overall forces involved in mechanical thrombectomy and can be used to develop safer and more effective stent retrievers for the most difficult cases.

Predictors of distal embolization during thrombectomy for anterior circulation large vessel bifurcation occlusion stroke.

Distal embolization is a frequent complication of mechanical thrombectomy (MT) for acute ischemic stroke, often leading to poor clinical outcomes. The vascular bifurcations represent a specialized anatomical location, thereby augmenting the complexity of MT. The specific factors contributing to distal embolization in this context have not been thoroughly explored. This study seeks to identify the factors associated with distal embolization during MT in patients with anterior circulation large vessel bifurcation occlusion stroke. A retrospective analysis was conducted on patients who underwent MT for acute anterior circulation bifurcation occlusion stroke between January 2015 and December 2023. Baseline characteristics, procedural details, and clinical outcomes were assessed. Univariate and multivariable analyses were performed to identify predictors of distal embolization during MT. The study included 119 patients. Univariate analysis revealed significant associations between distal embolization and occlusion location, internal carotid artery (ICA) tortuosity, first-line thrombectomy strategy, and the number of device passes. Multivariate analysis identified ICA bifurcation occlusions (odds ratio (OR) 3.21, 95% confidence interval (CI) 1.188 to 8.672, P=0.021), stent retriever thrombectomy (SRT) (OR 6.177, 95% CI 1.77 to 21.555, P=0.004), and a higher number of device passes (OR 1.778, 95% CI 1.132 to 2.792, P=0.013) as independent predictors of distal embolization. ICA bifurcation occlusion, the use of SRT, and an increased number of device passes are significant predictors of distal embolization during MT in patients with anterior circulation large vessel bifurcation occlusion strokes.

The Prognostic Value of a Naples Score in Determining in-Hospital Mortality in Patients with Acute Ischemic Stroke Undergoing Endovascular Treatment.

Background/Objectives: The Naples prognostic score (NPS), reflecting inflammation and nutritional status, has prognostic value, especially in cancer. This study evaluated its ability to predict in-hospital mortality in acute ischemic stroke (AIS) patients undergoing endovascular treatment (EVT). Methods: We retrospectively studied 244 patients with AIS who were admitted between April 2020 and December 2023. Patients were included if they presented within 6 h of symptom onset with evidence of intracranial proximal arterial occlusion. The EVT was performed using aspiration catheters, stent retrievers, or both. The NPS was calculated based on the neutrophil-lymphocyte ratio, lymphocyte-monocyte ratio, and albumin and total cholesterol levels. Results: We found a significant association between higher NPS scores and in-hospital mortality. Patients with a high NPS (3 or 4) had a mortality rate of 41.6% compared to 21.0% in the low-NPS group (0, 1, or 2). The full model incorporating NPS showed superior predictive ability for in-hospital mortality compared with the baseline model (areas under the curve 0.881 vs. 0.808). A receiver-operating characteristic analysis at a cutoff of >2.5 for the NPS showed a sensitivity of 86.6% and specificity of 41.9%. This study demonstrated that incorporating the NPS into the predictive model improved the accuracy and calibration for predicting in-hospital mortality. A decision curve analysis showed the net benefit of using the full model incorporating NPS over the baseline model, emphasizing its potential clinical application in prognostication. Conclusions: NPS is a reliable predictor of in-hospital mortality in AIS patients undergoing EVT. Incorporating NPS into clinical practice could help to identify high-risk patients and improve outcomes through tailored interventions.

Frictional forces in stent retriever procedures: The impact of vessel diameter, angulation, and deployment position.

Mechanical thrombectomy has improved the outcome of patients with acute ischemic stroke, but complications such as subarachnoid hemorrhage (SAH) can worsen the prognosis. This study investigates the frictional forces exerted by stent retrievers (SRs) on vessel walls, hypothesizing that these forces contribute to vascular stress and a risk of hemorrhage. We aimed to understand how vessel diameter, curvature, and stent deployment position influence these forces. Using a silicone vascular model simulating the middle cerebral artery, we created virtual vessels with diameters of 2.0 mm and 2.5 mm, each with branching angles of 60° and 120°. A Trevo NXT (4 × 28 mm) SR was deployed and retracted through these models, measuring the maximum static frictional force at the moment the SR began to move. The stent deployment position relative to the curvature (straight, distal 1/4, center, and proximal 1/4) was also varied to assess its impact on frictional forces. Each condition was tested 15 times, and the results were statistically analyzed. The highest frictional force was observed in the 2.0 mm/120° model, followed by the 2.0 mm/60°, 2.5 mm/120°, and 2.5 mm/60° models. Narrower and more sharply curved vessels exhibited significantly higher frictional forces. Friction also increased with more distal stent deployment, particularly in the narrower vessels. Smaller vessel diameters, greater curvature, and more distal stent deployment positions increase frictional forces during thrombectomy, potentially leading to SAH. These findings highlight the importance of selecting appropriately sized SRs and considering stent deployment positions to minimize vascular stress.

Clinical Impact of Reperfusion Techniques and Occlusion Sites in Thrombectomy: Insights from the ASSIST Stroke Registry

Background Mechanical thrombectomy has changed the landscape of acute ischemic stroke treatment, offering improved outcomes for patients with large vessel occlusions. The interplay between reperfusion techniques and occlusion sites remains a critical consideration in treatment decisions. This study investigates the impact of primary reperfusion techniques—stent retriever classic, stent retriever combination with aspiration, and direct aspiration—on procedural and clinical outcomes at different occlusion sites. Methods Using data from the ASSIST registry, a prospective multinational initiative, patients with anterior circulation acute ischemic stroke with large vessel occlusions (n = 1477) were included. Three primary occlusion sites—M1 segment of the middle cerebral artery, M2 segment of the middle cerebral artery, and the internal carotid artery—were studied. Univariate tests and multivariable logistic regression models were used to assess associations between reperfusion techniques and procedural and clinical outcomes, including the expanded thrombolysis in cerebral infarction score and the modified Rankin Scale, stratified by occlusion site. Results Achieving expanded thrombolysis in cerebral infarction ≥2c after first pass was lower in internal carotid artery occlusions (18.2%, P &lt;0.0001) with direct aspiration alone compared with stent retriever classic (38.2%) or stent retriever combination with aspiration (43.3%), while no differences were seen for M1 segment of the middle cerebral artery ( P = 0.77) and M2 segment of the middle cerebral artery ( P = 0.29) occlusions. Bailout maneuvers, which were more frequent in the direct aspiration group for all occlusion sites, did not result in longer procedure times or different final recanalization outcomes in direct aspiration compared with stent retriever classic or stent retriever combination with aspiration. Overall, there were no differences in the rate of patients with modified Rankin Scale scores of 0–2 at 90 days. No differences in safety outcomes were observed. Conclusions This study provides insight into the complex relationship between reperfusion techniques and occlusion sites in patients with acute ischemic stroke and shows that certain techniques have advantages in certain occlusion sites. As the field evolves, further research is warranted to refine our understanding of these dynamics and inform clinical practice.

A Woven EndoBridge dislodging from an aneurysm 12 days after the implantation procedure: illustrative case.

The Woven EndoBridge (WEB) is an effective embolization device. A few cases of WEB migration have been reported as adverse events, and most occurred during the procedure. A case of internal carotid artery (ICA) occlusion due to a trapped WEB, which occurred 12 days after the implantation procedure, is reported. A woman in her 70s was referred for an enlarged left ICA aneurysm during follow-up. A WEB SL 5 × 3 was chosen as the embolic device, and the implantation procedure was completed uneventfully. The patient's postoperative course was good, and she was discharged from the hospital. However, 12 days later, she was brought to the authors' hospital because the WEB device was trapped and occluded in the left ICA. The trapped WEB could not be retrieved using a gooseneck snare or stent retriever, but suction from a Sofia catheter released the trapped device, allowing it to be repositioned within the aneurysm. Most cases of WEB migration occur during surgery. In the present case, migration occurred 12 days after surgery, and to the best of the authors' knowledge, no similar cases have been reported. It is important to keep in mind that there are cases similar to the current case. https://thejns.org/doi/10.3171/CASE24278.

Can the clot meniscus and claw signs predict thrombectomy and clinical outcomes in patients with stroke? A systematic review and meta-analysis

BackgroundThe angiographic shape of an occlusion, like the clot meniscus sign and the claw sign, has been reported to potentially impact the recanalization rate and clinical outcome in patients undergoing...

Effect of thrombolysis type on the efficacy of aspiration versus stent retriever first line thrombectomy: results from the AcT trial

BackgroundIntravenous (IV) tenecteplase is increasingly being used in lieu of alteplase for acute ischemic stroke. We sought to study the influence of IV tenecteplase versus IV alteplase on the efficacy...