First-Pass Reperfusion by Mechanical Thrombectomy in Acute M1 Occlusion: The Size of Retriever Matters

Stent retriever size and outcomes after anterior circulation occlusion thrombectomy

BACKGROUND

The impact of stent retriever size on mechanical thrombectomy (MT) outcomes remains uncertain. We aim to clarify the influence of stent retriever size on MT outcomes by analyzing data from two national prospective registries.

METHODS

A retrospective analysis was performed on data from the French and German MT registries including consecutive patients with anterior circulation large vessel occlusion who underwent Solitaire stent retriever MT with or without additional aspiration. Efficacy outcomes were successful reperfusion and complete reperfusion. Safety outcomes included any intracerebral hemorrhage (ICH) and symptomatic intracerebral hemorrhage (sICH).

RESULTS

Complete reperfusion was lower in the 4×20 mm stent retriever group than in the 4×40 mm stent retriever group (47% vs 53%; OR 0.61, P=0.0039). Successful reperfusion did not differ between the 4×20 mm and 4×40 mm stent retriever groups (89% vs 93%; OR 0.69, P=0.25). There was no difference between the 6×30/6×40 mm and 4×20 mm stents, and there was no difference in functional outcomes between the groups. In terms of safety, any ICH was lower in the 4×20 mm group than in the 4×40 mm group (20% vs 36%; OR 0.60, P=0.0095). Symptomatic ICH was lower in the 4×20 mm group than in the 4×40 mm group (5% vs 10%; OR 0.58, P=0.086), but the difference did not reach statistical significance. Mortality was lower in the 4×20 mm than in the 6×40 mm group (26% vs 33%; OR 0.70, P=0.044). When compared according to occlusion location, the results were overall similar.

CONCLUSION

This study suggests that longer and larger stent retrievers lead to a higher reperfusion rate but also a higher rate of hemorrhagic complications. Overall, the size of the stent did not affect functional outcomes.

Dumbbell-shaped thrombectomy device for cerebral venous sinus thrombus removal with controllable axial and longitudinal maneuverability

Cerebral venous sinus thrombosis (CVST) is frequently observed in younger adults and features in large thrombus volume. Due to the triangular-like cross-sectional shape and large diameter of the superior sagittal sinus, all the commercially available artery stent retrievers are not suitable for venous vessels. In this study, a dumbbell-like stent was designed and fabricated by 3D braided technology using NiTi wires; it was manually rotatable and stretchable with controlled length/diameter ratios (2.6-14.0) and reciprocating maneuverability. Computational modeling and an in vitro study were conducted to evaluate the mechanical properties of this device and its ability to trap and remove thrombi from occluded venous vessels was verified by using a swine model. A single-center retrospective clinical study of 10 patients using the Venus-TD to treat patients with CVST was also conducted. Pre/postoperative thrombus volume in 10 patients was quantitatively analysed (12 855.3 ± 6417.1 vs. 2373.1 ± 2759.0 mm³, P < 0.001) with a high recanalization rate, yielding favorable clinical outcomes. This study offers a novel treatment option for patients with extensive CVST.

A retrospective study of the Dual-channels Bolus Contrast Injection (Dc-BCI) technique during endovascular mechanical thrombectomy in the management of acute ischemic stroke due to large-vessel occlusion: a technical report

Endovascular mechanical thrombectomy (EMT) is an effective treatment for acute ischemic stroke and identifying the precise thrombus size remains key to a successful EMT. However, no imaging modality has been able to provide this information simultaneously and efficiently in an emergency setting. The present study introduces a novel technique named dual-channel bolus contrast injection (Dc-BCI) for determining thrombus size and location during EMT. In the in vitro study, the Dc-BCI demonstrated an accurate projection of the thrombus size, as the actual thrombus diameter (R2 = 0.92, p < 0.01) and length (R2 = 0.94, p < 0.01) exhibited a high degree of correlation with that of obtained from Dc-BCI. Consequently, between February 2023 and August 2024, 87 patients diagnosed with acute cerebral large vessel occlusions were enrolled in the study and received EMT for the treatment of acute cerebral large vessel occlusions. The Dc-BCI was successfully performed in all patients to measure the diameter and length of the thrombus. These information were used to select an appropriate stent-retriever for EMT. The restoration of blood flow was achieved in 84 patients (96.6%) to an mTICI score of 2b/3. Additionally, a low incidence of postoperative complications was observed (e.g., subarachnoid hemorrhage 8% and cerebral hemorrhage 5.7%). In conclusion, it can be posited that the Dc-BCI has the potential to enhance the outcomes of EMT, as it is capable of revealing the thrombus size information, which optimizes the interaction between the stent retriever and the thrombus, while simultaneously reducing the risk of vascular injury that is associated with the prolonged use of the stent retriever.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Effect of Intravenous Tirofiban Versus Placebo on First-Pass Successful Reperfusion in Endovascular Stroke Thrombectomy: Insights From the RESCUE BT Randomized Clinical Trial

BACKGROUND

First-pass successful reperfusion (FPSR), defined as a successful/complete reperfusion achieved after a single thrombectomy pass, is predictive of favorable outcome in patients with acute ischemic stroke with large-vessel occlusion. It is unknown whether intravenous tirofiban is effective in increasing the rate of FPSR in acute anterior large-vessel occlusion stroke.

METHODS AND RESULTS

Patients who had acute large-vessel occlusion stroke presenting within 24 hours and underwent endovascular thrombectomy were analyzed from the RESCUE BT (Intravenous Tirofiban for Patients With Large Vessel Occlusion Stroke) clinical trial, of which the main analysis was neutral. The RESCUE BT trial randomized patients to receive either intravenous tirofiban or placebo before endovascular thrombectomy. The primary end point was FPSR, defined as successful reperfusion (extended thrombolysis in cerebral infarction scale 2b50, 2c, or 3) at first thrombectomy attempt. A modified Poisson regression analysis assessed the association between intravenous tirofiban treatment and FPSR. Of 948 enrolled patients, 463 patients were randomized to the tirofiban group and 485 to the placebo group. The mean age was 67 years, and 41.0% of the patients were women. FPSR was achieved more often in the tirofiban group (30.5% versus 23.5%; adjusted risk ratio, 1.24 [95% CI, 1.01-1.51]; P=0.04). FPSR was associated with a favorable shift to lower modified Rankin Scale disability levels at 90 days (common odds ratio, 1.42 [95% CI, 1.08-1.86]; P=0.01).

CONCLUSIONS

In this post hoc analysis of the RESCUE BT trial, treatment with intravenous tirofiban before endovascular thrombectomy was associated with increased FPSR in patients with acute ischemic stroke due to large-vessel occlusion in the anterior circulation. FPSR was associated with reduced 90-day levels of disability.

REGISTRATION

URL: http://chictr.org; Unique Identifier: ChiCTR-INR-17014167.

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

Introduction

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.

Methods

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.

Results

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).

Conclusion

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.

The initial experience with the Embotrap III stent-retriever in a real world setting

MATERIALS AND METHODS

We performed a retrospective review of our prospectively maintained database to identify all patients treated with the Embotrap 3 stent-retriever between January 2021 and January 2022. We recorded the baseline demographics, NIHSS, ASPECT score and clot characteristics, first pass and final eTICI scores, complications and 90 day mRS.

RESULTS

One hundred and ten patients met the inclusion criteria, average age 69 ± 14 years, 50% were male (n = 55). The median NIHSS at presentation was 18 (range 3-30) and 58.2% received IV tPA prior to MT. The median ASPECT score on plain CT was 8 with average clot length 20.2 ± 14.8 mm (n = 93). The first pass effect (FPE) was seen in 41.8% of cases with modified FPE seen in 59.1%. A 24-hour CT scan (n = 97) showed median ASPECTs of 7. 43.8% of patients achieve mRS ≤ 2 at 90-day mRS (n = 64).

CONCLUSION

The Embotrap 3 stent-retriever has a high rate of FPE and final recanalization in this real world cohort of patients.

Stent-retriever characteristics and strategies associated with recanalization in thrombectomy for acute ischemic stroke

INTRODUCTION

Predictive factors for successful reperfusion in mechanical thrombectomy for acute ischemic stroke, and especially technical factors, remain controversial. We investigated various techniques for better angiographic outcomes.

METHODS

In this retrospective study, acute ischemic stroke patients with large vessel occlusion treated with mechanical thrombectomy with combined technique were included. Scoring of the reperfusion grade for each attempt was conducted, and each attempt was divided into two groups based on successful reperfusion, which was defined using the presence or absence of modified thrombolysis in cerebral infarction 2b-3. The following characteristics were evaluated: the choice of stent-retriever, its length, occlusion site, thrombus position relative to deployed stent-retriever, methods of thrombectomy, and successful advancement of the distal access catheter to the proximal end of the thrombus.

RESULTS

Among 251 patients who underwent mechanical thrombectomy, 154 patients (255 attempts: mTICI 0-2a group, n = 119; mTICI 2b-3 group, n = 136) were included in the analysis. The thrombus position relative to the deployed stent-retriever was likely associated with successful reperfusion, although it was not statistically significant (proximal two-thirds 56.8 %; distal one-third 44.3 %, p = 0.09). Successful advancement of the distal access catheter was related to successful reperfusion both in univariate analysis (success 57.9 %; fail 35.8 %, p < 0.01) and in multivariate regression analysis (odds ratio 2.45; 95 % confidence interval: 1.30-4.61, p < 0.01).

CONCLUSIONS

Successful advancement of the distal access catheter to the proximal end of thrombus might be a key component for successful reperfusion in mechanical thrombectomy.

Impact of obesity-related indicators on first-pass effect in patients with ischemic stroke receiving mechanical thrombectomy

PURPOSE

The first-pass effect (FPE), defined as complete revascularization after a single thrombectomy pass in large vessel occlusion, is a predictor of good prognosis in patients with acute ischemic stroke (AIS) receiving mechanical thrombectomy (MT). We aimed to evaluate obesity-related indicators if possible be predictors of FPE.

METHODS

We consecutively enrolled patients with AIS who were treated with MT between January 2019 and December 2021 at our institution. Baseline characteristics, procedure-related data, and laboratory test results were retrospectively analyzed. A multivariable logistic regression analysis was performed to evaluate the independent predictors of FPE.

RESULTS

A total of 151 patients were included in this study, of whom 47 (31.1%) had FPE. After adjusting for confounding factors, the independent predictors of achieving FPE were low levels of body mass index (BMI) (OR 0.85, 95% CI 0.748 to 0.971), non-intracranial atherosclerotic stenosis (OR 4.038, 95% CI 1.46 to 11.14), and non-internal carotid artery occlusion (OR 13.14, 95% CI 2.394 to 72.11). Patients with lower total cholesterol (TC) (< 3.11 mmol/L) were more likely to develop FPE than those with higher TC (≥ 4.63 mmol/L) (OR 4.280; 95% CI 1.24 to 14.74) CONCLUSION: Lower BMI, non-intracranial atherosclerotic stenosis, non-internal carotid artery occlusion, and lower TC levels were independently associated with increased rates of FPE in patients with AIS who received MT therapy. FPE was correlated with better clinical outcomes after MT.

Enhancing the First-Pass Effect in Acute Stroke: The Impact of Stent Retriever Characteristics

Introduction: Although stentrievers (SRs) have been a mainstay of mechanical thrombectomy (MT), and current guidelines recommend the use of SRs in the treatment of large vessel occlusion stroke (LVO), there is a paucity of studies in the literature comparing SRs directly against each other in terms of mechanical and functional properties. Timely access to endovascular therapy and the ability to restore intracranial flow in a safe, efficient, and efficacious manner have been critical to the success of MT. This study aimed to investigate the impact of contemporary SR characteristics, including model, brand, size, and length, on the first-pass effect (FPE) in patients with acute ischemic stroke. Methods: Consecutive patients with M1 occlusion treated with a single SR+BGC were recruited from the ROSSETTI registry. The primary outcome was the FPE that was defined as modified (mFPE) or true (tFPE) for the achievement of modified thrombolysis in cerebral infarction (mTICI) grades 2b-3 or 3 after a single device pass, respectively. We compared patients who achieved mFPE with those who achieved tFPE according to SR characteristics. Results: We included 610 patients (52.3% female and 47.7% male, mean age 75.1 ± 13.62 years). mFPE was achieved in 357 patients (58.5%), whereas tFPE was achieved in 264 (43.3%). There was no significant association between SR characteristics and mFPE or tFPE. Specifically, the SR size did not show a statistically significant relationship with improvement in FPE. Similarly, the length of the SR did not yield significant differences in the mFPE and tFPE, even when the data were grouped. Conclusions: Our data indicate that contemporary SR-mediated thrombectomy characteristics, including model, brand, size, and length, do not significantly affect the FPE.

Cost-Effectiveness of a Direct-Aspiration First-Pass Technique versus Stent Retriever in Mechanical Thrombectomy

OBJECTIVE

A direct-aspiration first-pass technique (ADAPT) in mechanical thrombectomy has been described in recent studies as an efficacious strategy compared with using a stent retriever (SR). We sought to evaluate for cost differences of ADAPT technique versus SR as an initial approach.

METHODS

We conducted a retrospective analysis of consecutive patients with mechanical thrombectomy at our institution between 2022 and 2023. Patients were grouped into ADAPT with/without SR as a rescue strategy and SR as an initial approach with allowance of concomitant aspiration. Direct cost data (consumables) were obtained. Baseline demographics, stroke metrics, procedure outcomes and cost, and last follow-up outcomes in modified Rankin Scale were compared between 2 groups.

RESULTS

Fifty-six patients were included. Thirty-seven (66.1%) underwent ADAPT, with 11 (29.7%) eventually requiring an SR. Mean age was 64.8 years. The average National Institutes of Health Stroke Scale score was 13.2 in the ADAPT group and 14.0 in the SR group (P = 0.68), with a similar proportion of tissue plasminogen activator (P = 0.53), site of occlusion (P = 0.66), and tandem occlusion (P = 0.69) between the groups. Recanalization was achieved in 94.6% of all patients, with an average of 1.9 passes, 89.3% being TICI 2B or above, with no differences between the 2 groups. Significantly lower cost (P < 0.01) was observed in ADAPT ($14,243.4) compared with SR ($19,003.6). Average follow-up duration was 180.2 days, with mortality of 23.2%. At last follow-up, 55.4% remained functionally independent (modified Rankin Scale score <3) with no difference (P = 0.56) between the ADAPT (59.5%) and SR (47.4%) groups.

CONCLUSIONS

Outcomes were comparable between the ADAPT and SR groups. ADAPT reduced procedural consumables cost by approximately $5000 (25%), even if stent retrievers were allowed to be used for rescue. Establishing ADPAT as initial approach may bring significant direct cost savings while obtaining similar outcomes.

Impact of stent-retriever tip design on distal embolization during mechanical thrombectomy: a randomized in vitro evaluation

BACKGROUND

Repeated number of passes, clot fragmentation, and distal embolization during mechanical thrombectomy (MT) lead to worse clinical outcomes in acute ischemic stroke. This study aimed to assess the recanalization and embolic outcomes of different stent-retrievers (SRs): open-tip SR (Solitaire X 6×40 mm), closed-tip SR (EmboTrap II 5×33 mm), and filter-tip SR (NeVa NET 5.5×37 mm).

METHODS

Stiff-friable clot analogs were used to create middle cerebral artery (M1-MCA) occlusions in a benchtop model. After occlusion, experiments were randomized into one of the three treatment arms. The thrombectomy technique consisted of retrieving the SR into a balloon guide catheter under proximal flow arrest and continuous aspiration. A total of 150 single-attempt cases were performed (50 cases/treatment arm). Distal emboli (>100 µm) were collected and analyzed after each experiment.

RESULTS

Filter-tip SR achieved a non-significantly higher first-pass recanalization rate than open-tip SR and closed-tip SR (66% vs 48% vs 44%; P=0.064). Filter-tip SR prevented clot fragments>1 mm from embolizing distal territories in 44% of cases, compared with 16% in open-tip SR and 20% in closed-tip (P=0.003). There were no significant differences between treatment arms in terms of total emboli count (open-tip=19.2±13.1, closed-tip=19.1±10.7, filter-tip=17.2±13.0; P=0.660). Nonetheless, the number of large emboli (>1 mm) and total area of emboli were significantly lower in the filter-tip arm (n=0.88±1.2, A=2.06±1.85 mm2) than in the closed-tip arm (n=2.34±3.38, A=4.06±4.80 mm2; P<0.05).

CONCLUSIONS

When facing fragment-prone clots, the filter-tip SR significantly reduces the number of large clots (>1 mm) that embolize distally during an MT procedure, which in turn may increase the chances of first-pass complete recanalization.

Predictive Factors of First-Pass Effect in Patients Who Underwent Successful Endovascular Thrombectomy for Emergent Large Vessel Occlusion

OBJECTIVE

The primary treatment goal of current endovascular thrombectomy (EVT) for emergent large-vessel occlusion (ELVO) is complete recanalization after a single maneuver, referred to as the 'first-pass effect' (FPE). Hence, we aimed to identify the predictive factors of FPE and assess its effect on clinical outcomes in patients with ELVO of the anterior circulation.

METHODS

Among the 129 patients who participated, 110 eligible patients with proximal ELVO (intracranial internal carotid artery and proximal middle cerebral artery) who achieved successful recanalization after EVT were retrospectively reviewed. A comparative analysis between patients who achieved FPE and all others (defined as a non-FPE group) was performed regarding baseline characteristics, clinical variables, and clinical outcomes. Multivariate logistic regression analyses were subsequently conducted for potential predictive factors with p<0.10 in the univariate analysis to determine the independent predictive factors of FPE.

RESULTS

FPE was achieved in 31 of the 110 patients (28.2%). The FPE group had a significantly higher level of functional independence at 90 days than did the non-FPE group (80.6% vs. 50.6%, p=0.002). Pretreatment intravenous thrombolysis (IVT) (odds ratio [OR], 3.179; 95% confidence interval [CI], 1.025-9.861; p=0.045), door-to-puncture (DTP) interval (OR, 0.959; 95% CI, 0.932-0.987; p=0.004), and the use of balloon guiding catheter (BGC) (OR, 3.591; 95% CI, 1.231-10.469; p=0.019) were independent predictive factors of FPE.

CONCLUSION

In conclusion, pretreatment IVT, use of BGC, and a shorter DTP interval were positively associated with FPE, increasing the chance of acquiring better clinical outcomes.

Double stent-retriever as the first-line approach in mechanical thrombectomy: a randomized in vitro evaluation

BACKGROUND

A repeated number of passes during mechanical thrombectomy leads to worse clinical outcomes in acute ischemic stroke. Initial experiences with the simultaneous double stent-retriever (double-SR) technique as the first-line treatment showed promising safety and efficacy results.

OBJECTIVE

To characterize the potential benefits of using the double-SR as first-line technique as compared with the traditional single-SR approach.

METHODS

Three types of clot analogs (soft, moderately stiff, and stiff) were used to create terminal internal carotid artery (T-ICA=44) and middle cerebral artery (MCA=88) occlusions in an in vitro neurovascular model. Sixty-six cases were randomized into each treatment arm: single-SR or double-SR, in combination with a 0.071" distal aspiration catheter. A total of 132 in vitro thrombectomies were performed. Primary endpoints were the rate of first-pass recanalization (%FPR) and procedural-related distal emboli.

RESULTS

FPR was achieved in 42% of the cases. Overall, double-SR achieved a significantly higher %FPR than single-SR (52% vs 33%, P=0.035). Both techniques showed similar %FPR in T-ICA occlusions (single vs double: 23% vs 27%, P=0.728). Double-SR significantly outperformed single-SR in MCA occlusions (63% vs 38%, P=0.019), most notably in saddle occlusions (64% vs 14%, P=0.011), although no significant differences were found in single-branch occlusions (64% vs 50%, P=0.275). Double-SR reduced the maximal size of the clot fragments migrating distally (Feret diameter=1.08±0.65 mm vs 2.05±1.14 mm, P=0.038).

CONCLUSIONS

This randomized in vitro evaluation demonstrates that the front-line double-SR technique is more effective than single-SR in achieving FPR when treating MCA bifurcation occlusions that present saddle thrombus.

Evaluation of effectiveness and safety of the multizone NeVaTM stent retriever for mechanical thrombectomy in ischemic stroke

PURPOSE

This study aimed to evaluate the effectiveness and safety of the NeVaTM stent retriever as first- and second-line device for mechanical thrombectomy in acute ischemic stroke.

METHODS

In this retrospective single-center study, all consecutive patients that underwent mechanical thrombectomy with NeVaTM stent retriever as first- or second-line device due to intracranial vessel occlusion with acute ischemic stroke between March and November 2022 were included.

RESULTS

Thirty-nine patients (m=18, f=21) with a mean age of 69.9 ± 13.3 years were treated with the NeVaTM stent retriever. NeVaTM stent retriever was used as first-line device in 24 (61.5%) of patients and in 15 (38.5%) as second-line device. First-pass rate (≥mTICI 2c) of NeVaTM stent retriever was both 66.7% when used as first- or second-line device. Final recanalization rate including rescue strategies was 92.3% for ≥mTICI2c and 94.9% for ≥mTICI2b. No device-related minor or major adverse events were observed. A hemorrhage was detected in 33.3% of patients at 24h post-thrombectomy dual-energy CT, of which none was classified as symptomatic intracerebral hemorrhage. NIHSS and mRS improved significantly at discharge compared to admission (p<0.05).

CONCLUSION

The NeVaTM stent retriever has a high effectivity and good safety profile as first- and second-line device for mechanical thrombectomy in acute ischemic stroke.

Evaluation of effectiveness and safety of the large-format pRESET 6-50 thrombectomy stent-retriever in the endovascular treatment of ischemic stroke: real-world experiences from two tertiary comprehensive stroke centers

Objective

Mechanical thrombectomy (MT) has become the standard treatment for acute ischemic stroke (AIS) with large vessel occlusion (LVO). First-pass (FP) reperfusion of the occluded vessel and fewer passes with stent retrievers show improvement in functional outcomes in stroke patients, while higher numbers of passes are associated with higher complication rates and worse outcomes. Studies indicate that a larger size of the stent-retriever is associated with a higher rate of first-pass reperfusion and improved clinical outcomes. In this retrospective study, we investigated the clinical performance of a recently developed and one of the largest stent-retrievers available in the treatment of LVO (pRESET 6-50, phenox GmbH, Bochum).

Materials and methods

All consecutive patients with ischemic stroke due to proximal large vessel occlusion treated with MT using the pRESET 6-50 stent-retriever in two tertiary stroke centers between 09/2021 and 07/2022 were included in this study. The reperfusion rate after MT was quantified by the modified thrombolysis in cerebral infarction (mTICI) score, and functional neurological outcome was evaluated with the National Institutes of Health Stroke Scale (NIHSS) score and the major early neurological recovery (mENR) rate after 24 h. Successful FP reperfusion was defined as mTICI ≥ 2b. Successful and complete reperfusion were defined as mTICI ≥ 2b and mTICI ≥ 2c, respectively.

Results

In total, 98 patients (52 men and 46 women) with a median age of 75 (range 25-95 years) were included. A total of 70 (72%) patients presented with an occlusion of the middle cerebral artery (MCA) in the M1 segment, 6 (6%) patients with an occlusion of the M2 segment, 17 (17%) patients with an occlusion of the internal carotid artery (ICA), and 5 (5%) patients with an occlusion of the obstructed basilar artery (BA). Successful FP reperfusion was achieved in 58 patients (62%). Successful and complete reperfusion were achieved in 95 (97%) and 82 (83%) patients, respectively. The median National Institutes of Health Stroke Scale (NIHSS) in all treated patients improved from 17 to 7.5. Major early neurological recovery (mENR) was observed in 34 patients (35.1%).

Conclusion

MT with the pRESET 6-50 stent-retriever achieves high successful first-pass and final reperfusion rates in patients with AIS and LVO. The results of this study support the thesis to use large-format stent-retriever in proximal vessel occlusion MT whenever feasible in order to improve high FP and final reperfusion rate, which are known predictors of good clinical outcome.

Improved first-pass effect in acute stroke thrombectomy using Solitaire-X compared to Solitaire-FR

Background

In acute ischemic stroke (AIS), successful endovascular thrombectomy (EVT) of large vessel occlusion (LVO) necessitates the most suited device. Solitaire-X has longer and larger diameter pusher wires than Solitaire-FR.As the role of a larger pusher-wire diameter is uncertain, we aim to compare procedural, clinical, and radiological outcomes for AIS patients undergoing EVT using either type of Solitaire device. Procedures were performed using the Solumbra technique, which combines a large-bore aspiration catheter with a stentriever. The primary outcome was to compare rates of successful first-pass recanalization (defined as TICI 2b/3 score). The secondary objectives were procedural (rates of successful recanalization), clinical (post-procedural NIHSS and days of hospitalization), and radiological (post-procedural ASPECT score and hemorrhagic transformation) outcome measures.

Design

Consecutive AIS patients undergoing EVT for LVO were recruited into a prospective multicenter database at our academic center. We have used Solitaire-FR until October 2020 and Solitaire-X ever since. We retrospectively analyzed our prospective consecutive registry. Included in our analysis are patients undergoing EVT using Solitaire only; patients with tandem lesions or underlying stenosis requiring emergent stenting during the procedure were excluded. The cohort of patients treated with Solitaire-X was compared with a cohort consisting of the most recent consecutive cases undergoing EVT with the Solitaire-FR.

Results

A total of 182 (71.9 ± 14, 61% male patients) AIS patients were included in the analysis with both groups (n = 91 each) sharing similar demographic characteristics, premorbid conditions, and stroke characteristics (time from symptom-onset, NIHSS, ASPECTS, occlusion site, and rates of intravenous-tPA treatment). The Solitaire-X group had a higher rate of first-pass recanalization (65.9% vs. 50.5%, p = 0.049). On 24-h post-procedural head-CT, the Solitaire-X group had higher ASPECT scores (6.51 ± 2.9 vs. 5.49 ± 3.4, p = 0.042) and lower post-procedural average bleeding volumes (0.67 ± 2.1 vs. 1.20 ± 3.4 mL, p = 0.041). The Solitaire-X group had shorter duration of hospitalization (16.6 ± 13.1 days vs. 25.1 ± 23.2, p = 0.033). On multivariate analysis, using Solitaire-X was the sole independent predictor of first-pass recanalization (OR 2.17, 95% CI 1.12-4.26, p = 0.023).

Conclusion

In our study, the use of the Stentriever-X with a larger pusher-wire diameter was associated with a higher likelihood of first-pass effect and improved procedural, clinical, and radiological outcomes in AIS patients.

The Stream Device-A Retrospective Review of 51 Cases

Mechanical thrombectomy is the gold-standard treatment for patients that have suffered large-vessel occlusion (LVO) stroke. Various different stent-retrievers, aspiration catheters, and techniques have been developed to perform this procedure. We present our initial results regarding the Stream device.

MATERIALS AND METHODS

We performed a retrospective review of a prospectively maintained database at our high-volume centre to identify all patients treated with the Stream device between February 2021 and January 2023. We recorded baseline demographics, NIHSS, ASPECT scores, eTICI scores, complications, and 90-day mRS.

RESULTS

We identified 51 patients, 49.0% of whom were male (n = 25), with a median age of 73 (range: 51-89) and a median NIHSS score of 17 (range 4-22), and 68.6% received IV tPA. The median ASPECT score was 10 (range 6-10). Hyperdense clots were seen in 34 cases (66.7%), with a mean clot length of 12 ± 6.2 mm (range 2-26 mm). Clots were located in the anterior circulation in 49 patients. The standard Stream device was used in 78.4% of cases, with Stream 17 being used in 19.6% of cases. The FPE was observed in 25.5% of cases (n = 13), with the mFPE being seen in 31.4% of cases (n = 16). A final eTICI score of ≥2b was achieved in 90.2% of cases (n = 46), and eTICI 2c/3 was seen in 84.3% of cases (n = 43). Furthermore, 24 h CT scans showed that the median ASPECT score was 8 (range 0-10). Good functional outcomes at 90 days (mRS ≤ 2) were achieved in 21.6% of cases (n = 11).

CONCLUSIONS

The Stream device shows acceptable rates of FPE and mFPE compared to existing devices. Further larger studies are required alongside an understanding of the optimal technique for this device's use.

First-Pass Effect Predicts Clinical Outcome and Infarct Growth After Thrombectomy for Distal Medium Vessel Occlusions

BACKGROUND

The first-pass effect in endovascular thrombectomy (EVT) has been associated with better clinical outcomes and decreased stroke progression in large vessel occlusion but has not been evaluated in distal, medium vessel occlusions (DMVOs).

OBJECTIVE

To assess the impact on clinical outcome and stroke progression of the modified first-pass effect (defined as a successful first-pass [modified Thrombolysis In Cerebral Infarction 2b/2c/3] revascularization) in patients who underwent EVT for a primary DMVOs.

METHODS

We collected data from consecutive patients who underwent EVT for a primary DMVO at a single large academic center. We compared the rate of good clinical outcome (modified Rankin Scale of 0-2 at 3 months) and stroke progression between patients who demonstrated modified first-pass effect (mFPE) vs those who did not (no-mFPE).

RESULTS

Between January 2018 and January 2021, we included 60 patients who underwent EVT for an acute ischemic stroke with a primary DMVO. Overall, mFPE was achieved in 32% (19/60) of EVTs. The mFPE was associated with a higher rate of good clinical outcome compared with no-mFPE (89% vs 46%, odds ratio = 16.04 [2.23-115.39], P = .006 in multivariate analysis). Final stroke volume was less among mFPE patients (6.9 mL [4.7-13.6] vs 23 mL [14.6-47], P = .001) as was stroke progression (6.8 mL [4-12.1] vs 17.8 mL [8.1-34.9], P = .016). The mFPE was still associated with higher rates of good clinical outcome when compared with patients reaching an modified Thrombolysis In Cerebral Infarction score ≥2b in more than 1 pass (89% vs 53%; odds ratio = 7.37 [1.43-38.08], P = .017).

CONCLUSION

The mFPE may be associated with better clinical outcomes and lower stroke progression in DMVO.

First Pass Effect and Location of Occlusion in Recanalized MCA M1 Occlusions

Background

The first pass effect has been shown to improve clinical outcomes in patients with middle cerebral artery (MCA) M1 occlusions.

Objective

To determine the rates of first pass effect in MCA M1 occlusions and determine if proximal or distal location of occlusion modified clinical outcomes.

Methods

Patients with recanalized MCA M1 occlusions who underwent endovascular thrombectomy (EVT) were reviewed to determine the effect of first pass effect (FPE) and location of occlusion on clinical outcomes. MCA occlusions were classified as proximal if they included the first two thirds of the MCA and involved the lenticulostriate vessels, or distal if they did not.

Results

We included 261 patients of which 27% achieved FPE. Of the cohort, there were 91 (35%) proximal MCA occlusions and 170 (65%) distal MCA occlusions. Baseline demographics and treatment time metrics were comparable across both groups. There was a trend toward good clinical outcome in patients with or without a FPE (60 vs. 46%; p = 0.06), however a higher rate of excellent clinical outcome was noted in patients with FPE (46 vs. 30%; p = 0.02). When compared by location, patients with distal MCA occlusions had a higher rate of excellent clinical outcome (40 vs. 25%; p = 0.02). Multivariable analysis showed that distal MCA occlusion was the strongest predictor of an excellent clinical outcome and first pass effect.

Conclusion

Patients with MCA M1 occlusions with FPE have a higher rate of excellent clinical outcomes compared to those who did not. Location of MCA occlusion appears to modify rates of first pass effect and excellent clinical outcomes.