Direct thromboaspiration efficacy for mechanical thrombectomy is related to the angle of interaction between the aspiration catheter and the clot

In vitro evaluation of how the presence of the stent retriever and microcatheter influences aspiration parameters in thrombectomy according to their position inside the aspiration catheter

BACKGROUND

Several variations of the combined thrombectomy technique for acute ischemic stroke using a stent retriever and aspiration catheter have been described. The aim of our study was to assess how the presence of the microcatheter and stent retriever affect the basic aspiration parameters, namely, flow rate and aspiration force, depending on their position within the aspiration catheter.

METHODS

Two experimental set-ups were designed to assess changes in flow rate and aspiration force according to the position of the stent retriever and microcatheter within the aspiration catheter.

RESULTS

The transition of the stent retriever and microcatheter from the distal to proximal position resulted in a progressive increase in the flow rate, but with no impact on aspiration force. Additionally, the size of the stent retriever had no significant effect on flow rate changes and the reduction in flow rate was related to the microcatheter diameter. Negative pressure generated inside the aspiration catheter impacted on its distal segment located beyond the radiopaque marker, thus leading to its partial collapse. As a consequence, the measured aspiration force was lower than the theoretical aspiration force level for all tested aspiration catheters.

CONCLUSIONS

In our experimental model, the position of the stent retriever and microcatheter within the aspirator catheter affected the flow rate, but not the aspiration force. Negative pressure generated within the aspiration catheter appeared to determine a partial collapse of the distal segment that resulted in a less effective aspiration force than the theoretical aspiration force level.

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.

Current Approaches and Methods to Understand Acute Ischemic Stroke Treatment Using Aspiration Thrombectomy

Acute ischemic stroke occurs when a blood clot occludes a cerebral artery. Mechanical interventions, primarily stent retrievers and aspiration thrombectomy, are used currently for removing the occluding clot and restoring blood flow. Aspiration involves using a long catheter to traverse the cerebral vasculature to reach the blood clot, followed by application of suction through the catheter bore. Aspiration is also used in conjunction with other techniques such as stent retrievers and balloon guide catheters. Despite the wide use of aspiration, our physical understanding of the process and the causes of the failure of aspiration to retrieve cerebral clots in certain scenarios is not well understood. Experimental and computational studies can help develop the capability to provide deeper insights into the procedure and enable development of new devices and more effective treatment methods. We recapitulate the aspiration-based thrombectomy techniques in clinical practice and provide a perspective of existing engineering methods for aspiration. We articulate the current knowledge gap in the understanding of aspiration and highlight possible directions for future engineering studies to bridge this gap, help clinical translation of engineering studies, and develop new patient-specific stroke therapy.

Impact of Target Artery Size on the Performance of Aspiration Thrombectomy: Insights from a Swine Model with Real-Time Visualization

A novel swine model was developed to investigate the underlying reasons for the failure of aspiration thrombectomy. The model allows direct visualization of the target artery during thrombectomy in vessels of different sizes. The behavior of the target artery undergoing aspiration thrombectomy was recorded with high-resolution digital microscopy and fluoroscopic visualization, providing valuable insight into how the different sizes of treated arteries affect the effectiveness of mechanical thrombectomy.

Assessment of the safety and efficacy of the Zoom 45 and 55 reperfusion catheters for medium and distal mechanical thrombectomies: A multi-institutional study

INTRODUCTION

The Zoom aspiration catheters harbor novel dimensions and construction to enhance trackability and deliverability. In addition, a beveled tip may improve thrombus interaction and aspiration force for a set inner diameter. This study evaluates their utility in medium and distal vessel occlusions.

OBJECTIVE

To evaluate the safety and efficacy of Zoom 45 and 55 aspiration catheters in medium and distal vessel thrombectomy.

METHODS

Patients treated for distal vessel occlusions via mechanical thrombectomy utilizing either the Zoom 45/55 catheter or a historical control catheter between 2021-2022 at two institutions were included in this study. Medium and distal occlusions were defined as any anterior or posterior cerebral artery branch as well as the M2-4 segment of the middle cerebral artery (MCA). Preprocedural, procedural, and postprocedural variables were obtained.

RESULTS

Thirty-eight patients underwent thrombectomy with Zoom 45 or 55 catheters; four had multiple occluded vessels. Occlusion location included the M2 in 32 cases, M3-4 in 7 cases, A2 in 2 cases and P2 in 1 case. The mean number of passes per occlusion was 1.6 and overall successful reperfusion (TICI 2b or greater) was achieved in 84 % of cases. There were no symptomatic procedure-related complications such as perforation or post-procedural symptomatic ICH. Modified Rankin scores rates of 0-2, 3-5, and 6 at three months post-procedure were 35.7 %, 21.4 %, and 42.9 %, respectively.

CONCLUSIONS

The Zoom beveled tip aspiration catheters are safe and effective for more challenging medium and distal vessel occlusions.

Optimizing catheter centering enhances mechanical thrombectomy success: Performance difference in cases using novel macrowires versus traditional microwires

BACKGROUND

The aim of this study is to determine how guidewire selection impacts procedure time and success and analyze if the trend toward the adoption of larger diameter guidewires provides a quantifiable advantage over traditional 0.014″ guidewires.

METHODS

A review of 494 consecutively performed acute ischemic stroke cases performed between 2018 and 2022 were reviewed and grouped into cases using a single 0.014″ outer diameter (OD) guidewire (195 cases) and cases using a single 0.018″ or 0.024″ OD guidewire (128 cases). These groups were compared for differences in average time to recanalization, average number of passes to achieve recanalization, and first pass success. Cases were compared overall, and further analyzed by region of occlusion to look at specific guidewire related differences for cases with M1, M2, and ICA occlusions.

RESULTS

Procedures using a larger OD guidewire have an average 5 min and 30 s reduction in time from puncture to recanalization (p = 0.0201). ICA occlusion cases using a larger macrowire show a 20 min reduction in recanalization time (p = 0.0005), a reduction in average number of passes from 2.6 to 1.7 (p = 0.0058), and an increase in first pass success from 18.8% to 58.3% when compared to traditional guidewires.

CONCLUSION

Large 0.018″ or 0.024″ OD guidewires better fill the lumen of the catheter and help to center the thrombectomy system in the vessel and navigate to the clot face. This leads to a reduction in procedure time and number of passes, and an increase in first pass success, especially when treating occlusions in the ICA.

Can micro-guidewire advancement forces predict clot consistency and location to assist the first-line technique for mechanical thrombectomy?

BACKGROUND

The identification of specific clot characteristics before mechanical thrombectomy (MTB) might allow the selection of the most effective first-line technique, thus potentially improving the procedural outcome. We aimed to evaluate if the microwire push forces could extrapolate information on clot consistency and extension before MTB, based on clot mechanical properties.

METHODS

We measured in vitro the forces exerted on the proximal extremity of the guidewire during the advancement and retrieval of the guidewire through clot analogs of different compositions. In addition, we analyzed the forces exerted on the guidewire to extrapolate information about the location of the proximal and distal extremities of the clot analogs.

RESULTS

The maximum forces recorded during the whole penetration phase were significantly different for hard and soft clots (median values, 55.6 mN vs 15.4 mN, respectively; P<0.0001). The maximum slope of the force curves recorded during the advancement of the guidewire for the first 3 s of penetration also significantly differentiated soft from hard clot analogs (7.6 mN/s vs 23.9 mN/s, respectively; P<0.0001). In addition, the qualitative analysis of the shape of the force curves obtained during the advancement and retrieval of the guidewire showed a good potential for the identification of the proximal and distal edges of the clot analogs.

CONCLUSION

Our results demonstrated that it was possible to differentiate between soft and hard clot analogs. Furthermore, force measurements could give important information about the location of the clot extremities. Such an approach might support the selection of the first-line MTB technique, with the potential to improve the outcome.

Early technique switch following failed passes during mechanical thrombectomy for ischemic stroke: should the approach change and when?

BACKGROUND

Fast and complete reperfusion in endovascular therapy (EVT) for ischemic stroke leads to superior clinical outcomes. The effect of changing the technical approach following initially unsuccessful passes remains undetermined.

OBJECTIVE

To evaluate the association between early changes to the EVT approach and reperfusion.

METHODS

Multicenter retrospective analysis of prospectively collected data for patients who underwent EVT for intracranial internal carotid artery, middle cerebral artery (M1/M2), or basilar artery occlusions. Changes in EVT technique after one or two failed passes with stent retriever (SR), contact aspiration (CA), or a combined technique (CT) were compared with repeating the previous strategy. The primary outcome was complete/near-complete reperfusion, defined as an expanded Thrombolysis in Cerebral Infarction (eTICI) of 2c-3, following the second and third passes.

RESULTS

Among 2968 included patients, median age was 66 years and 52% were men. Changing from SR to CA on the second or third pass was not observed to influence the rates of eTICI 2c-3, whereas changing from SR to CT after two failed passes was associated with higher chances of eTICI 2c-3 (OR=5.3, 95% CI 1.9 to 14.6). Changing from CA to CT was associated with higher eTICI 2c-3 chances after one (OR=2.9, 95% CI 1.6 to 5.5) or two (OR=2.7, 95% CI 1.0 to 7.4) failed CA passes, while switching to SR was not significantly associated with reperfusion. Following one or two failed CT passes, switching to SR was not associated with different reperfusion rates, but changing to CA after two failed CT passes was associated with lower chances of eTICI 2c-3 (OR=0.3, 95% CI 0.1 to 0.9). Rates of functional independence were similar.

CONCLUSIONS

Early changes in EVT strategies were associated with higher reperfusion and should be contemplated following failed attempts with stand-alone CA or SR.

Tortuosity of middle cerebral artery M1 segment and outcomes after mechanical thrombectomy

BACKGROUND

We aimed to quantify the tortuosity of the middle cerebral artery (MCA) and assess its effects on radiological and clinical outcomes in patients with acute MCA occlusions who received mechanical thrombectomy (MT).

METHODS

This retrospective study enrolled 53 patients with acute ischemic stroke due to MCA M1 or M2 segment occlusion who underwent MT using stent retrievers (SRs). Tortuosity index (TI) was defined to quantify the tortuosity of the MCA M1 segment using the following formula: (actual distance / straight distance) × 100. For each patient, four TIs were measured in the anteroposterior and caudal views for both ipsilateral and contralateral sides to the occluded site (TI-APi, TI-APc, TI-CAUi, and TI-CAUc, respectively) using magnetic resonance angiography (MRA) or computed tomography angiography (CTA). We defined the first-pass effect (FPE) as first-pass mTICI classification ≥2b reperfusion.

RESULTS

Patients who did not achieve FPE had significantly higher TI-APi (112 vs. 106; P = 0.004), TI-APc (111 vs. 105; P = 0.005), TI-CAUi (110 vs. 105; P = 0.002), and TI-CAUc (110 vs. 105; P = 0.001) than those who achieved FPE. In multivariable analysis, higher TI-APi, TI-CAUi, and TI-APc were independently associated with an increased rate of unsuccessful FPE (odds ratio (OR) [95% confidence interval (CI)]: 1.25 [1.02-1.61], 1.21 [1.01-1.45], and 1.27 [1.03-1.73], respectively). TI-CAUi, TI-APc, and TI-CAUc were also independent predictors of the occurrence of intracranial hemorrhage after MT (OR [95% CI]: 1.15 [1.01-1.38], 1.14 [1.01-1.38], 1.25 [1.02-1.52], respectively).

CONCLUSIONS

The TIs of the MCA M1 segment on both ipsilateral and contralateral sides were associated with unfavourable outcomes after MT.

Combined Technique for Internal Carotid Artery Terminus or Middle Cerebral Artery Occlusions in the ASTER2 Trial

BACKGROUND

The aim of this study was to report the results of a subgroup analysis of the ASTER2 trial (Effect of Thrombectomy With Combined Contact Aspiration and Stent Retriever vs Stent Retriever Alone on Revascularization in Patients With Acute Ischemic Stroke and Large Vessel Occlusion) comparing the safety and efficacy of the combined technique (CoT) and stent retriever as a first-line approach in internal carotid artery (ICA) terminus±M1-middle cerebral artery (M1-MCA) and isolated M1-MCA occlusions.

METHODS

Patients enrolled in the ASTER2 trial with ICA terminus±M1-MCA and isolated M1-MCA occlusions were included in this subgroup analysis. The effect of first-line CoT versus stent retriever according to the occlusion site was assessed on angiographic (first-pass effect, expanded Treatment in Cerebral Infarction score ≥2b50, and expanded Treatment in Cerebral Infarction score ≥2c grades at the end of the first-line strategy and at the end of the procedure) and clinicoradiological outcomes (24-hour National Institutes of Health Stroke Scale, ECASS-III [European Cooperative Acute Stroke Study] grades, and 3-month modified Rankin Scale).

RESULTS

Three hundred sixty-two patients were included in the postsubgroup analysis according to the occlusion site: 299 were treated for isolated M1-MCA occlusion (150 with first-line CoT) and 63 were treated for ICA terminus±M1-MCA occlusion (30 with first-line CoT). Expanded Treatment in Cerebral Infarction score ≥2b50 (odds ratio, 11.83 [95% CI, 2.32-60.12]) and expanded Treatment in Cerebral Infarction score ≥2c (odds ratio, 4.09 [95% CI, 1.39-11.94]) were significantly higher in first-line CoT compared with first-line stent retriever in patients with ICA terminus±M1-MCA occlusion but not in patients with isolated M1-MCA.

CONCLUSIONS

First-line CoT was associated with higher reperfusion grades in patients with ICA terminus±M1-MCA at the end of the procedure.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03290885.

"The microcatheter contrast injection technique": A novel technique to detect the proximal end of a thrombus in mechanical thrombectomy

Background: An aspiration catheter needs to attach to a thrombus in order to achieve first-pass recanalization by mechanical thrombectomy (MT) for acute ischemic stroke (AIS), particularly that using a direct aspiration first pass technique. The meniscus sign, which is defined as meniscoid contrast opacification indicating the proximal edge of a thrombus, has been suggested to contribute to successful recanalization. In some cases, the meniscus sign is not detected following an injection of contrast medium through a guiding catheter. To precisely identify the location of a thrombus, we use "the microcatheter contrast injection (MCI) technique," which accurately shows the proximal edge of a thrombus. We herein introduce this novel technique and discuss its efficacy in MT. Methods: In cases without the meniscus sign, a microcatheter was advanced to the distal end of contrast opacification, and contrast medium was injected through the microcatheter to detect the meniscus sign. An aspiration catheter was then advanced to the thrombus indicated by the meniscus sign and slowly withdrawn under aspiration. Results: 29 patients underwent MT for AIS using the MCI technique. Even in cases without the meniscus sign on initial angiography, the MCI technique accurately revealed the proximal edge of the thrombus. Moreover, middle cerebral artery occlusion due to atherosclerotic stenosis and displacement of the aspiration catheter and thrombus axis were detected using this technique. Conclusions: The MCI technique may effectively reveal the exact site of a thrombus and increase the success rate of first-pass recanalization.

In vitro testing of a funnel-tip catheter with different clot types to decrease clot migration in mechanical thrombectomy

BACKGROUND

Mechanical thrombectomy is the standard treatment for acute ischemic stroke in patients with large vessel occlusion and can be performed up to 24h after symptom onset. Despite high recanalization rates, embolism in new territories has been reported in 8.6% of the cases. Causes for this could be clot abruption during stent retrieval into the smaller opening of a standard distal access catheter, and antegrade blood flow via collaterals despite proximal balloon protection. A funnel-shaped tip with a larger internal diameter was developed to increase the rate of first-pass recanalization and to improve the safety and efficacy of mechanical thrombectomy.

METHODS

This in vitro study compared the efficacy of a funnel-shaped tip with a standard tip in combination with different clot compositions. Mechanical thrombectomy was performed 80 times for each tip, using two stent retrievers (Trevo XP ProVue 3/20 mm, 4/20 mm) and four different clot types (hard vs. soft clots, 0-24h vs. 72h aged clots).

RESULTS

Significantly higher first-pass recanalization rates (mTICI 3) were observed for the funnel-shaped tip, 70.0% versus 30.0% for the standard tip (absolute difference, 32; relative difference 57.1%; P < .001), regardless of the clot type and stent retriever. Recanalization could be increased using harder Chandler loop clots versus softer statically generated clots, as well as 0-24h versus 72h aged clots, respectively.

CONCLUSION

The funnel-shaped tip achieved higher first-pass recanalization rates than the smaller standard tip and lower rates of clot abruption at the tip. Clot compositions and aging times impacted recanalization rates.

Network meta-analysis of first-line thrombectomy strategy for acute posterior circulation strokes: a preliminary evaluation for combined approach

Objective

Thrombectomy may provide superior results compared to best medical care for acute posterior circulation strokes (PCS). Contact aspiration (CA), stent retriever (SR), and combined SR + CA (SRA) are commonly employed as first-line techniques. However, the optimal strategy and the role of SRA remain uncertain.

Methods

Systematic searching was conducted in three databases (PubMed, Embase, and Cochrane). Network meta-analyzes were performed using random-effects models. The reperfusion and clinical outcomes were compared. Pooled outcomes were presented as odds ratios (OR) with 95% confidence intervals (CI). Rankograms with surface under the cumulative ranking curve (SUCRA) were calculated.

Results

Seventeen studies were included, involving a total of 645 patients who received first-line CA, 850 patients who received SR, and 166 patients who received SRA. Regarding final recanalization outcomes, both first-line SRA (OR = 3.2, 95%CI 1.4-11.0) and CA (OR = 2.1, 95%CI 1.3-3.7) demonstrated superiority over SR in achieving successful reperfusion [modified Thrombolysis In Cerebral Infarction (mTICI) 2b-3], with values of SUCRA 91.1, 58.5, and 0.4%, respectively. In addition, first-line SRA showed an advantage in achieving final mTICI 2c/3 compared to CA (OR = 3.6, 95%CI 0.99-16.0) and SR (OR = 6.4, 95%CI 1.3-35.0), with SUCRA value of 98.0, 44.7, and 7.2%, respectively. Regarding reperfusion outcome after the first pass, SRA also achieved a higher rate of mTICI 3 than SR (OR = 4.1, 95%CI 1.3-14.0), while CA did not (SUCRA 97.4, 4.6, 48.0%). In terms of safety outcomes, first-line CA was associated with a lower incidence of symptomatic intracranial hemorrhage (sICH) compared to SR (OR = 0.38, 95%CI 0.1-1.0), whereas the SRA technique did not (SUCRA 15.6, 78.6, 55.9%). Regarding clinical prognosis, first-line CA achieved a higher proportion of functional independence (modified Rankin Scale (mRS) 0-2) at 90 days than SR (OR = 1.4, 95%CI 1.1-1.9), whereas SRA did not (SUCRA 90.5, 17.4, 42.1%).

Conclusion

For acute PCS, a first-line CA strategy yielded better results in terms of final successful reperfusion and 90-day functional independence compared to SR. As the combined technique, first-line SRA was associated with superior first-pass and final reperfusion outcomes compared to SR. However, no significant difference was observed in functional independence achieved by first-line SRA compared to the other two strategies. Further high-quality studies are warranted.

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.

Devices and Techniques

This extensive review explores the intricacies of the three principal mechanical thrombectomy techniques: the stent retriever technique, contact aspiration technique, and a combined approach, and their application in managing acute ischemic stroke. Each technique operates uniquely on the thrombus, leading to differences in their efficacy. Factors including clot size, clot stiffness, vessel tortuosity, and the angle of interaction between the aspiration catheter and the clot significantly influence these differences. Clinical trials and meta-analyses have shown the overall equivalency of these techniques for the treatments of large vessel occlusion and distal medium vessel occlusions. However, there are nuanced differences that emerge under specific clinical circumstances, highlighting the absence of a one-size-fits-all strategy in acute ischemic stroke management. We emphasize the need for future investigations to elucidate these nuances further, aiming to refine procedural strategies and individualize patient care for optimal outcomes.

Impact of vessel tortuosity and radiological thrombus characteristics on the choice of first-line thrombectomy strategy: Results from the ESCAPE-NA1 trial

INTRODUCTION

Despite improvements in device technology, only one-third of stroke patients undergoing endovascular thrombectomy (EVT) achieve first-pass effect (FPE). We investigated the effect of arterial tortuosity and thrombus characteristics on the relationship between first-line EVT strategy and angiographic outcomes.

PATIENTS AND METHODS

Patients with thin-slice baseline CT-angiography from the ESCAPE-NA1 trial (Efficacy and safety of nerinetide for the treatment of acute ischemic stroke) were included. Tortuosity was estimated using the tortuosity index extracted from catheter pathway, and radiological thrombus characteristics were length, non-contrast density, perviousness and hyperdense artery sign. We assessed the association of first-line EVT strategy (stent-retriever [SR] versus contact aspiration [CA] versus combined SR+CA) with FPE (eTICI score 2c/3 after one pass), final eTICI 2b/3, number of passes and procedure duration using multivariable regression. Interaction of tortuosity and thrombus characteristics with first-line technique were assessed using interaction terms.

RESULTS

Among 520 included patients, SR as a first-line modality was used in 165 (31.7%) patients, CA in 132 (25.4%), and combined SR+CA in 223 (42.9%). FPE was observed in 166 patients (31.9%). First-line strategy was not associated with FPE. Tortuosity had a significant effect on FPE only in the CA group (aOR = 0.90 [95% CI 0.83-0.98]) compared with stent-retrievers and combined first-line approach (p interaction = 0.03). There was an interaction between thrombus length and first-line strategy for number of passes (p interaction = 0.04). Longer thrombi were associated with higher number of passes only in the CA group (acOR 1.03 [95% CI 1.00-1.06]).

CONCLUSION

Our study suggests that vessel tortuosity and longer thrombi may negatively affect the performance of first-line contact aspiration catheters in acute stroke patients undergoing EVT.

Improved catheter delivery for aspiration thrombectomy using Tenzing 7 ledge reducing catheter and FreeClimb 70

PURPOSE

Previous comparative mechanical thrombectomy device trials reported a substantial crossover rate from first-line aspiration to stent-retriever thrombectomy. A specialized delivery catheter may help track large-bore aspiration catheters to target occlusions. We report our multicenter experience of aspiration thrombectomy of intracranial large vessel occlusions using the FreeClimb^TM 70 and Tenzing® 7 delivery catheter (Route 92, San Mateo, CA).

METHODS

After local Institutional Review Board approval, we retrospectively reviewed the clinical, procedural, and imaging data of patients who underwent mechanical thrombectomy with the FreeClimb 70 and Tenzing 7.

RESULTS

FreeClimb 70 was successfully delivered using Tenzing 7 to target occlusion in 30/30 (100%) patients (18 M1, 6 M2, 4 ICA-terminus, and 2 basilar artery occlusions), without the use of a stent-retriever for anchoring. In 21/30 (70%) cases, a leading microwire was not needed to advance the Tenzing 7 to the target. Median (interquartile range) time from groin puncture to first pass was 12 (interquartile range 8-15) minutes. Overall first pass effect, or first pass effect (modified thrombolysis in cerebral ischemia 2C-3), was achieved 16/30 (53%). For M1 occlusions, first pass effect was 11/18 (61%). Successful reperfusion (modified thrombolysis in cerebral ischemia ≥ 2B) was achieved in 29/30 (97%) cases after a median of 1 pass (interquartile range 1-3). Median groin puncture to reperfusion time was 16 (interquartile range 12-26) minutes. There were no procedural complications or symptomatic intracranial hemorrhage. Average improvement in National Institutes of Health Stroke Scale at discharge was 6.6  ±  7.1. There were three patient deaths (renal failure, respiratory failure, and comfort care).

CONCLUSIONS

Initial data support the use of Tenzing 7 with FreeClimb 70 catheter for reliable access to rapid, effective, and safe aspiration thrombectomy of large vessel occlusions.

Functional and technical outcomes in acute ischemic stroke patients with hyperdense middle cerebral artery sign treated with endovascular thrombectomy

Background and objective

The hyperdense middle cerebral artery sign (HMCAS) is observed in a proportion of patients with acute ischemic stroke (AIS). This sign reflects the presence of an intravascular thrombus rich in red blood cells. Several studies have demonstrated that HMCAS increases the risk of poor outcomes in AIS patients treated with IV thrombolysis or no reperfusion therapy; however, whether HMCAS predicts a poor outcome in patients treated with endovascular thrombectomy (EVT) is less clear. We aimed to evaluate the functional outcome by the modified Rankin scale (mRS) at 90 days and technical challenges in patients with HMCAS undergoing EVT.

Methods

We studied 143 consecutive AIS patients with middle cerebral artery M1 segment or internal carotid artery + M1 occlusions who underwent EVT.

Results

There were 73 patients (51%) with HMCAS. Patients with HMCAS had a higher frequency of cardioembolic stroke (p = 0.038); otherwise, no other baseline difference was observed. No differences in functional outcomes (mRS) at 90  days (p = 0.698), unfavorable outcomes (mRS > 2) (p = 0.929), frequency of symptomatic intracranial hemorrhage (p = 0.924), and mortality (mRS-6) (p = 0.736) were observed between patients with and without HMCAS. In patients with HMCAS, EVT procedures were 9  min longer, requiring a higher number of passes (p = 0.073); however, optimal recanalization scores (modified thrombolysis in cerebral infarction: 2b-3) were equally achieved by both groups.

Conclusion

Patients with HMCAS treated with EVT do not have a worse outcome at 3  months compared with no-HMCAS patients. Patients with HMCAS required a greater number of thrombus passes and longer procedure times.

Initial Experience Using the New pHLO 0.072-inch Large-Bore Catheter for Direct Aspiration Thrombectomy in Acute Ischemic Stroke

PURPOSE

A direct aspiration, first pass technique (ADAPT) has been introduced as a rapid and safe thrombectomy strategy in patients with intracranial large vessel occlusion (LVO). The aim of the study is to determine the technical feasibility, safety, and functional outcome of ADAPT using the newly released large bore pHLO 0.072-inch aspiration catheter (AC; Phenox).

MATERIALS AND METHODS

We performed a retrospective analysis of data collected prospectively (October 2019-November 2021) from 2 comprehensive stroke centers. Accessibility of the thrombus, vascular recanalization, time to recanalization, and procedure-related complications were evaluated. National Institutes of Health stroke scale scores at presentation and discharge and the modified Rankin scale (mRS) score at 90 days post-procedure were recorded.

RESULTS

Twenty-five patients (14 female, 11 male) with occlusions of the anterior circulation were treated. In 84% of cases, ADAPT led to successful recanalization with a median procedure time of 28 minutes. In the remaining cases, successful recanalization required (to a total of 96%; modified thrombolysis in cerebral infarction score 2b/3) the use of stent retrievers. No AC-related complications were reported. Other complications included distal migration of the thrombus, requiring a stent-retriever, and symptomatic PH2 hemorrhage in 16% and 4%, respectively. After 3 months, 52% of the patients had mRS scores of 0-2 with an overall mortality rate of 20%.

CONCLUSION

Results from our retrospective case series revealed that thrombectomy of LVOs with pHLO AC is safe and effective in cases of large-vessel ischemic stroke. Rates of complete or near-complete recanalization after the first pass with this method might be used as a new benchmark in future trials.

Three-dimensional rotational angiography improves mechanical thrombectomy recanalization rate for acute ischaemic stroke due to middle cerebral artery M2 segment occlusions

BACKGROUND

Occlusions of the middle cerebral artery (MCA) M2 segments can be difficult to address with mechanical thrombectomy (MTB) using standard projections and this can affect the final recanalization. Three-dimensional rotational angiography (3D-RA) allows to obtain a 3D model of cerebral vessels in a few seconds and to determine the best two-dimensional (2D) projections to be selected to evaluate and treat cerebrovascular diseases, such as aneurysms or vascular malformations. We aimed to determine if 3D-RA could be applied also in MTB.

METHODS

A retrospective review of two patient cohorts treated during two time periods of 12 months before and after the introduction of 3D-RA use at our institution for MTB in M2 occlusions. Analyses were conducted to compare the two groups for procedural characteristics, such as timing, recanalization rate and complications and clinical outcome.

RESULTS

One hundred acute ischaemic stroke (AIS) patients (3D-RA group = 57; controls = 43) underwent MTB for an M2 occlusion during the two study periods. Recanalization rates were significantly higher in cases treated with 3D-RA. The mean 3D technique thrombectomy time was compared to that of non-3D cases (47 vs. 49 min, respectively).

CONCLUSIONS

Our findings showed that 3D-RA is a useful tool to select specific working projections to AIS patients presenting an M2 occlusion by improving final recanalization compared to standard projections, without increasing the overall procedural time.

Mechanical thrombectomy with a novel beveled tip aspiration catheter: A technical case report

Recent data suggested aspiration thrombectomy as the first-pass approach in endovascular treatment of acute stroke and is accepted as a safe and efficient alternative to stent-retriever thrombectomy. The efficiency of mechanical thrombectomy for complete removal of the clot is directly related to the catheter trackability, aspiration force, and inner diameter of the aspiration catheter. Zoom 71 Aspiration catheter (Imperative Care, Campbell, California, USA) is a novel aspiration catheter with a beveled tip aiming to increase the tip surface area, increased suction force, and advanced trackability. This case report describes the successful use of Zoom 71 aspiration catheter in a left middle cerebral artery M2 branch occlusion and highlights technical details including navigation without the support of a microcatheter microwire combination.

Magnetic Resonance Angiography and Cisternography fused images in acute ischemic stroke may save time during endovascular procedure revealing vessel anatomy

Background and purpose

Endovascular treatment (EVT) is a time-dependent procedure that aims to remove the arterial blood flow obstruction in brain vessels in acute ischemic stroke. In our center, the MRI patient selection protocol in acute ischemic stroke is performed with DWI, FLAIR, MR angiography (MRA) and MR cisternography (MRC) sequences. MRA and MRC are promptly and automatically fused in order to have a clear detection of vessel anatomy, before and during EVT.

Our study aim is to evaluate if the fusion process between MRA and MRC could be considered time-safe and could influence EVT duration or outcome.

Materials and methods

45 patients were retrospectively selected for the study and divided into 2 groups according to the presence of MRC sequence fused with MRA (Group 1) or not (Group 2 - controls).

Results

MRA and MRC fusion was able to depict vessel anatomy in all subjects of Group 1 (22 patients, 12 females; age 75.59 years ± 10.87). Group 1 presented EVT time reduction (p < 0.05;p = 0.040) (51.59 min ± 30.94) when compared to Group 2 (23 patients, 13 females; age 75.04 years ± 12.12) (71.96 min ± 34.55) of 20.37 min average. No differences between groups were detected evaluating: NIHSS at admission (p = 0.49) and discharge (p = 0.67), pre-stroke mRS (p = 0.89), mRS at 90 days (p = 0.62), ASPECT (p = 0.98) and ASPECT-DWI scores (p = 0.93), time from symptom onset to groin puncture (p = 0.80), thromboaspiration vs combined technique (p = 0.67), EVT success (p = 0.63).

Conclusion

Fusion of MRA and MRC is a safe and promising technique in promptly revealing vascular anatomy beyond vessel obstruction, and can play a role in EVT duration reduction.

REACT Aspiration Catheters: Clinical Experience and Technical Considerations

Aspiration catheters are widely used in mechanical thrombectomy procedures to treat acute ischemic stroke due to large vessel occlusion. The key performance requirements for aspiration catheters are ease of navigation and effective aspiration. In this work, we review the clinical experience and in vitro studies of REACT aspiration catheters (Medtronic, Minneapolis, MN, USA). In vitro experiments showed that REACT catheters exhibit solid performance in navigation and aspiration. Previous studies reported that the recanalization capacity of the aspiration catheters can be influenced by the devices’ inner diameter and tip distensibility, the catheter-to-vessel diameter ratio, the negative pressure delivered by the vacuum generator, the cyclical aspiration mode, the proximal flow arrest, and the angle of interaction between catheter and clot. REACT catheters can be navigated through the vasculature without any support from a microcatheter/ microwire in favorable anatomical configurations. In challenging situations, mostly encountered when crossing the ophthalmic segment of the internal carotid artery, the use of the stentriever anchoring technique or delivery assist catheter can facilitate the navigation. Three clinical studies reporting on 299 patients who underwent mechanical thrombectomy with REACT catheters were included in this review. Successful recanalization (modified treatment in cerebral ischemia score 2b–3) was achieved in 89–96% of cases, no procedural complications related to REACT catheters were reported, and functional independence (modified Rankin Scale 0–2) at 90-days was 24–36%. In vitro experimental evaluations and clinical studies support the safety and effectiveness of the REACT catheters.

Stent-Based Retrieval Techniques in Acute Ischemic Stroke Patients with and Without Susceptibility Vessel Sign

BACKGROUND AND PURPOSE

Randomized controlled trials have challenged the assumption that reperfusion success after mechanical thrombectomy varies depending on the retrieval techniques applied; however, recent analyses have suggested that acute ischemic stroke (AIS) patients showing susceptibility vessel sign (SVS) may respond differently. We aimed to compare different stent retriever (SR)-based thrombectomy techniques with respect to interventional outcome parameters depending on SVS status.

METHODS

We retrospectively reviewed 497 patients treated with SR-based thrombectomy for anterior circulation AIS. Imaging was conducted using a 1.5 T or 3 T magnetic resonance imaging (MRI) scanner. Logistic regression analyses were performed to test for the interaction of SVS status and first-line retrieval technique. Results are shown as percentages, total values or adjusted odds ratio (aOR) with 95% confidence intervals (CI).

RESULTS

An SVS was present in 87.9% (n = 437) of patients. First-line SR thrombectomy was used to treat 293 patients, whereas 204 patients were treated with a combined approach (COA) of SR and distal aspiration. An additional balloon-guide catheter (BGC) was used in 273 SR-treated (93.2%) and 89 COA-treated (43.6%) patients. On logistic regression analysis, the interaction variable of SVS status and first-line retrieval technique was not associated with first-pass reperfusion (aOR 1.736, 95% CI 0.491-6.136; p = 0.392), overall reperfusion (aOR 3.173, 95% CI 0.752-13.387; p = 0.116), periinterventional complications, embolization into new territories, or symptomatic intracerebral hemorrhage. The use of BGC did not affect the results.

CONCLUSION

While previous analyses indicated that first-line SR thrombectomy may promise higher rates of reperfusion than contact aspiration in AIS patients with SVS, our data show no superiority of any particular SR-based retrieval technique regardless of SVS status.

A high resolution scanning electron microscopy analysis of intracranial thrombi embedded along the stent retrievers

Endovascular treatment with stent retriever thrombectomy is a major advancement in the standard of care in acute ischemic stroke (AIS). The modalities through which thrombi embed along stent retriever following mechanical thrombectomy (MTB) have not yet been elucidated. Using scanning electron microscopy (SEM), we analyzed the appearance of thrombi retrieved by MTB from AIS patients, when embedded into the stent retriever. We observed that the organization and structural compactness vary for compositionally different thrombi. The modalities of attachment onto the stent vary according to thrombus composition and organization.

First-line contact aspiration versus first-line stent retriever for acute ischemic stroke with M2 occlusion: A systematic review and meta-analysis

OBJECTIVE

Mechanical thrombectomy is widely used for acute ischemic stroke caused by middle cerebral artery M2 segment occlusion. However, the comparison between contact aspiration (CA) and stent retriever (SR) used as first-line techniques for acute M2 occlusion is still unclear. We aimed to perform a systematic review and meta-analysis on this issue.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement was followed. Three databases (Pubmed, Embase, and Cochrane) were searched. The Newcastle-Ottawa scale was used to assess the risk of bias for the included studies. We focused on two main outcomes, the final successful reperfusion (modified Thrombolysis in Cerebral Infarction mTICI 2b/3) and 90-day functional independence (modified Rankin Scale score 0-2). The meta-analyses were performed using the random-effects models.

RESULTS

Seven observational studies were included for systematic review. Only one study indicated a superiority of first-line SR in achieving final successful reperfusion, while the other six studies did not show significant difference between these two techniques. And all the seven studies showed comparable proportion of 90-day functional independence. Five studies were available for meta-analysis with 601 patients (239 received first-line CA, 362 received first-line SR). The pooled results also suggested that the proportion of final successful reperfusion (OR=1.18, 95%CI 0.72-1.93, I2 =0%) and 90-day functional independence (OR=1.18, 95%CI 0.82-1.68, I2 =0%) were comparable between these two strategies.

CONCLUSION

For patients with acute M2 occlusion, first-line CA and SR techniques could achieve similar final reperfusion outcomes and 90-day clinical prognosis. Further studies with randomized controlled design are needed.

Comparison of stent retriever thrombectomy using 3-dimensional patient-specific models of intracranial circulation with actual middle cerebral artery occlusion thrombectomy cases

BACKGROUND AND PURPOSE

Stent retriever (SR) thrombectomy is commonly used for the treatment of emergent large vessel occlusion (ELVO) in acute ischemic stroke. Clot imaging parameters such as clot length, diameter, distance to the internal carotid artery terminus, and vessel angle where the SR is deployed may predict the likelihood of achieving first pass effect (FPE). Most of the proposed factors that seem to affect recanalization success have been studied individually, and conflicting data derived from clinical versus in vitro studies using 3-dimensional printed models of intracranial circulation currently exist.

METHODS

Using patient-specific 3-dimensional phantoms of the cervical and intracranial circulation, we simulated middle cerebral arteries (MCA) M1 and M2 occlusions treated with SR thrombectomy using Solitaire (Medtronic) or Trevo (Styker). Our primary outcome was FPE, defined as Thrombolysis in Cerebral Infarction score of 2c-3 achieved after a single thrombectomy attempt. We also performed retrospective analysis of same clot imaging characteristics of consecutive cases of MCA occlusion and its association with FPE matching the 3-dimensional in vitro experiments. Analysis was conducted using IBM SPSS Statistics Version 25 (IBM Corp., Armonk, NY). Chi-square tests and bivariate logistic regressions were the main statistical tests used in analysis. A p-value of less than .05 was considered to indicate statistical significance. Ninety-five confidence intervals (95% CI) were generated.

RESULTS

We compared 41 thrombectomy experiments performed using patient-specific 3-dimensional in vitro models with a retrospective cohort of 41 patients treated with SR thrombectomy. We found that in the in vitro cohort, higher MCA angulation was associated with a lower likelihood of FPE (odds ratio [OR] = 0.967, 95% CI = 0.944-0.991, p = .008). Meanwhile in the in vivo cohort, higher MCA angulation was associated with a higher likelihood of FPE (OR = 1.039, 95% CI = 1.003-1.077, p = .033). Neither clot length nor location of clot (M1 vs. M2) was associated with a difference in FPE rates in either cohort.

DISCUSSION

Comparison of SR thrombectomy performed during actual MCA occlusion cases versus patient-specific 3-dimensional replicas revealed MCA angulation as an independent predictor of procedure success or failure. However, the opposite direction of effect was observed between the two studied environments, indicating potential limitations of studying SR thrombectomy using 3-dimensional models of LVO.

Internal Carotid Artery Tortuosity: Impact on Mechanical Thrombectomy

Background:

Although tortuosity of the internal carotid artery (ICA) can pose a significant challenge when performing mechanical thrombectomy, few studies have examined the impact of ICA tortuosity on mechanical thrombectomy outcomes.

Methods:

In a registry-based hospital cohort, consecutive patients with anterior circulation stroke in whom mechanical thrombectomy was attempted were divided into 2 groups: those with tortuosity in the extracranial or cavernous ICA (tortuous group) and those without (nontortuous group). The extracranial ICA tortuosity was defined as the presence of coiling or kinking. The cavernous ICA tortuosity was defined by the posterior deflection of the posterior genu or the shape resembling Simmons-type catheter. Outcomes included first pass effect (FPE; extended Thrombolysis in Cerebral Infarction score 2c/3 after first pass), favorable outcome (3-month modified Rankin Scale score of 0–2), and intracranial hemorrhage.

Results:

Of 370 patients, 124 were in the tortuous group (extracranial ICA tortuosity, 35; cavernous ICA tortuosity, 70; tortuosity at both sites, 19). The tortuous group showed a higher proportion of women and atrial fibrillation than the nontortuous group. FPE was less frequently achieved in the tortuous group than the nontortuous group (21% versus 39%; adjusted odds ratio, 0.45 [95% CI, 0.26–0.77]). ICA tortuosity was independently associated with the longer time from puncture to extended Thrombolysis in Cerebral Infarction ≥2b reperfusion (β=23.19 [95% CI, 13.44–32.94]). Favorable outcome was similar between groups (46% versus 48%; P=0.87). Frequencies of any intracranial hemorrhage (54% versus 42%; adjusted odds ratio, 1.61 [95% CI, 1.02–2.53]) and parenchymal hematoma (11% versus 6%; adjusted odds ratio, 2.41 [95% CI, 1.04–5.58]) were higher in the tortuous group. In the tortuous group, the FPE rate was similar in patients who underwent combined stent retriever and contact aspiration thrombectomy and in those who underwent either procedure alone (22% versus 19%; P=0.80). However, in the nontortuous group, the FPE rate was significantly higher in patients who underwent combined stent retriever and contact aspiration (52% versus 35%; P=0.02).

Conclusions:

ICA tortuosity was independently associated with reduced likelihood of FPE and increased risk of postmechanical thrombectomy intracranial hemorrhage.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02251665.

A Meta-analysis of Combined Aspiration Catheter and Stent Retriever versus Stent Retriever Alone for Large-Vessel Occlusion Ischemic Stroke

BACKGROUND

The efficacy of combined aspiration catheter and stent retriever compared with stent retriever alone for the treatment of large-vessel occlusion acute ischemic stroke is unclear.

PURPOSE

Our aim was to conduct a systematic literature review and meta-analysis on several metrics of efficacy comparing aspiration catheter and stent retriever with stent retriever alone.

DATA SOURCES

MEDLINE and the Cochrane Library Databases were searched. Randomized controlled trials and case-control and cohort studies were included.

STUDY SELECTION

Ten comparative studies were included detailing a combined 1495 patients with aspiration catheter and stent retriever and 1864 with stent retrievers alone.

DATA ANALYSIS

Data on first pass effect (TICI 2b/2c/3 after first pass), final successful reperfusion (modified TICI ≥2b), and 90-day functional independence (mRS ≤ 2) were collected. Meta-analysis was performed using a random-effects model.

DATA SYNTHESIS

There was a pooled composite first pass effect of 40.8% (611/1495) versus 32.6% (608/1864) for aspiration catheter and stent retriever and stent retriever alone, respectively (P < .0001). Similarly, on a meta-analysis, aspiration catheter and stent retriever were associated with a higher first pass effect compared with stent retriever alone (OR = 1.63; 95% CI, 1.20-2.21; P = .002; I² = 72%). There was no significant difference in composite rates of successful reperfusion between aspiration catheter and stent retriever (72.8%, 867/1190) and stent retriever alone (70.8%, 931/1314) (P = .27) or on meta-analysis (OR = 1.31; CI, 0.81-2.12; P = .27; I² = 82%). No difference was found between aspiration catheter and stent retriever and stent retriever alone on 90-day functional independence (OR = 1.02; 95% CI, 0.77-1.36; P = .88; I² = 40%).

LIMITATIONS

This study is limited by high interstudy heterogeneity.

CONCLUSIONS

On meta-analysis, aspiration catheter and stent retriever are associated with a superior first pass effect compared with stent retriever alone, but they are not associated with statistically different final reperfusion or functional independence.

Aspects of ischemic stroke biomechanics derived using ex-vivo and in-vitro methods relating to mechanical thrombectomy

Establishing the underlying biomechanics of acute ischemic stroke (AIS) and its treatment is fundamental to developing more effective clinical treatments for one of society's most impactful diseases. Recent changes in AIS management, driven by clinical evidence of improved treatments, has already led to a rapid rate of innovation, which is likely to be sustained for many years to come. These unprecedented AIS triage and treatment innovations provide a great opportunity to better understand the disease. In this article we provide a perspective on the recreation of AIS in the laboratory to inform contemporary device design and procedural techniques in mechanical thrombectomy. Presentation of these findings, which have been used to solve the applied problem of designing mechanical thrombectomy devices, is intended to help inform the development of basic biomechanics solutions for AIS.

Revascularization Outcome Prediction for A Direct Aspiration-First Pass Technique (ADAPT) from Pre-Treatment Imaging and Machine Learning

A direct aspiration-first pass technique (ADAPT) has recently gained popularity for the treatment of large vessel ischemic stroke. Here, we sought to create a machine learning-based model that uses pre-treatment imaging metrics to predict successful outcomes for ADAPT in middle cerebral artery (MCA) stroke cases. In 119 MCA strokes treated by ADAPT, we calculated four imaging parameters-clot length, perviousness, distance from the internal carotid artery (ICA) and angle of interaction (AOI) between clot/catheter. We determined treatment success by first pass effect (FPE), and performed univariate analyses. We further built and validated multivariate machine learning models in a random train-test split (75%:25%) of our data. To test model stability, we repeated the machine learning procedure over 100 randomizations, and reported the average performances. Our results show that perviousness (p = 0.002) and AOI (p = 0.031) were significantly higher and clot length (p = 0.007) was significantly lower in ADAPT cases with FPE. A logistic regression model achieved the highest accuracy (74.2%) in the testing cohort, with an AUC = 0.769. The models had similar performance over the 100 train-test randomizations (average testing AUC = 0.768 ± 0.026). This study provides feasibility of multivariate imaging-based predictors for stroke treatment outcome. Such models may help operators select the most adequate thrombectomy approach.

Bridging therapy and direct mechanical thrombectomy in the treatment of cardiogenic cerebral infarction with anterior circulation macrovascular occlusion

BACKGROUND

Intravenous thrombolysis is an important treatment for cerebral infarction. However, it is difficult to achieve good results if the patient is complicated with anterior circulation macrovascular occlusion. In addition, the vascular recanalization rate is low, so mechanical thrombectomy, that is, bridging therapy, is needed

AIM

To investigate the efficacy and safety of bridging therapy and direct mechanical thrombectomy in the treatment of cardiogenic cerebral infarction with anterior circulation macrovascular occlusion.

METHODS

Ninety-six patients in our hospital with cardiogenic cerebral infarction with anterior circulation macrovascular occlusion from January 2017 to July 2020 were divided into a direct thrombectomy group (n = 48) and a bridging group (n = 48). Direct mechanical thrombectomy was performed in the direct thrombectomy group, and bridging therapy was used in the bridging treatment group. Comparisons were performed for the treatment data of the two groups (from admission to imaging examination, from admission to arterial puncture, from arterial puncture to vascular recanalization, and from admission to vascular recanalization), vascular recanalization rate, National Institutes of Health Stroke Scale (NIHSS) and Glasgow Coma Scale (GCS) scores before and after treatment, prognosis and incidence of adverse events.

RESULTS

In the direct thrombectomy group, the time from admission to imaging examination was 24.32 ± 8.61 min, from admission to arterial puncture was 95.56 ± 37.55 min, from arterial puncture to vascular recanalization was 54.29 ± 21.38 min, and from admission to revascularization was 156.88 ± 45.51 min, and the corresponding times in the bridging treatment group were 25.38 ± 9.33 min, 100.45 ± 39.30 min, 58.14 ± 25.56 min, and 161.23 ± 51.15 min; there were no significant differences between groups (P=0.564, 0.535, 0.426, and 0.661, respectively). There was no significant difference in the recanalization rate between the direct thrombectomy group (79.17%) and the bridging group (75.00%) (P = 0.627). There were no significant differences between the direct thrombectomy group (16.69 ± 4.91 and 12.12 ± 2.07) and the bridging group (7.13 ± 1.23 and (14.40 ± 0.59) in preoperative NIHSS score and GCS score (P = 0.200 and 0.203, respectively). After the operation, the NIHSS scores in both groups were lower than those before the operation, and the GCS scores were higher than those before the operation. There was no significant difference in NIHSS and GCS scores between the direct thrombectomy group (6.91 ± 1.10 and 14.19 ± 0.65) and the bridging group (7.13 ± 1.23 and 14.40 ± 0.59) (P = 0.358 and 0.101, respectively). There was no significant difference in the proportion of patients who achieved a good prognosis between the direct thrombectomy group (52.08%) and the bridging group (50.008%) (P = 0.838). There was no significant difference in the incidence of adverse events between the direct thrombectomy group (6.25%) and the bridging group (8.33%) (P = 0.913).

CONCLUSION

Bridging therapy and direct mechanical thrombectomy can safely treat cardiogenic cerebral infarction with anterior circulation macrovascular occlusion, achieve good vascular recanalization effects and prognoses, and improve the neurological function of patients.

A Direct Aspiration First Pass Technique for Vertebra-Basilar Occlusion: A Retrospective Comparison to Stent Retriever

OBJECTIVES

This study aimed to assess the clinical usefulness of a direct aspiration first pass technique as a first-line strategy for mechanical thrombectomy in posterior circulation.

MATERIALS AND METHODS

We examined 34 consecutive patients treated with mechanical thrombectomy for acute vertebrobasilar artery occlusion. Procedural and clinical outcomes were assessed and compared between patients treated with a direct aspiration first pass technique first-line strategy (ADAPT group) and stent retriever system first-line strategy (stent retriever group).

RESULTS

Overall, successful reperfusion, complete reperfusion, and first-pass effects were achieved in 94.1%, 61.8%, and 50% of patients with acute ischemic stroke in vertebra-basilar artery occlusion treated with mechanical thrombectomy, respectively. The ADAPT group required a significantly shorter procedural time (p=.015) and fewer attempts (p=.0498) to achieve successful recanalization than the stent retriever group. The ADAPT group also tended to show better recanalization rates and first-pass effects than the stent retriever group. The rates of favorable outcomes seemed to be better, although insignificant, in the ADAPT group than in the stent retriever group (52.2% vs. 27.3%, p=.217). However, a significant correlation between the time required for reperfusion and clinical outcome was detected, and this will serve as the rationale for encouraging a direct aspiration first pass technique as a first-line strategy in the acute vertebra-basilar artery.

CONCLUSIONS

The a direct aspiration first pass technique first-line strategy for mechanical thrombectomy in posterior circulation may achieve successful recanalization with fewer attempts and shorter durations than the stent retriever first-line strategy.

Comparison of aspiration versus combined technique as first-line approach in terminal internal carotid artery occlusion: a multicenter experience

BACKGROUND

There is no consensus on the most effective endovascular technique to use in patients with acute ischemic stroke due to terminal internal carotid artery (ICA) occlusion. The aim of this study was to compare safety and efficacy of the aspiration technique (AT) and combined technique (CT) as first-line approach in terminal ICA occlusions.

METHODS

We performed a retrospective analysis of prospectively collected databases from seven Italian stroke centers. Patients were divided into two subgroups according to the first-line approach: AT group or CT group. We followed the STROBE guidelines for cohort studies. We used Chi-square test, one-way and multivariate ANOVA analysis, together with contrast analysis and post hoc tests, logistic regression and Pearson's bivariate correlation for the statistical analyses.

RESULTS

Between January 2018 and August 2020, 353 patients were treated for a terminal ICA occlusion, with either AT or CT. CT was associated with a higher Thrombolysis in Cerebral Infarction (TICI) 2B-3 after the first pass (51.0% vs 26.9%) and at the end of the procedure (84% vs 73.3%) and with an improved clinical outcome at discharge (modified Rankin Scale (mRs) 0-2 of 47.8% vs 34.0%) and at 3 months' follow-up (mRs 0-2 of 56.5% vs 38.9%) compared with AT.

CONCLUSION

Thrombectomy of terminal ICA occlusions obtained using CT as first-line approach demonstrated better technical and functional outcomes in comparison with AT.

Mechanical thrombectomy beyond the circle of Willis: efficacy and safety of different techniques for M2 occlusions

BACKGROUND

M2 segment occlusions represent approximately one-third of non-lacunar ischemic stroke and can lead to permanent neurological deficits. Various techniques are available for mechanical thrombectomy beyond the circle of Willis, but data evaluating their effectiveness and safety are lacking.

METHODS

A retrospective review of patients with ischemic stroke undergoing mechanical thrombectomy for M2 occlusions from 13 centers in North American and Europe was performed. Tandem or multiple-territory occlusions were excluded. The primary outcome was 90-day modified Rankin Scale and reperfusion rates across stent-retriever, direct aspiration and combined techniques.

RESULTS

There were 465 patients (mean age 71.48±14.03 years, 53.1% female) with M2 occlusions who underwent mechanical thrombectomy. Stent-retriever alone was used in 133 (28.6%), direct aspiration alone in 93 (20.0%) and the combined technique in 239 (51.4%) patients. Successful reperfusion was achieved with the combined technique in 198 (82.2%; OR 2.6 (1.1-6.9)), with stent-retriever alone in 112 (84.2%; OR 9.2 (1.9-44.6)) and with direct aspiration alone in 62 (66.7%; referencecategory). Intraprocedural subarachnoid hemorrhages (iSAH) were 36 (7.7%) and were more likely to occur in patients treated with the stent-retrievers (OR 5.0 (1.1-24.3)) and combined technique (OR 4.6 (1.1-20.9)). Good clinical outcome was achieved in 260 (61.8%) patients, while 59 (14.0%) patients died. Older age, higher baseline NIHSS (National Institutes of Health Stroke Scale), parenchymal hemorrhage and iSAH were associated with poor outcome while successful recanalization and higher baseline ASPECTS (Alberta Stroke Program Early CT Score) were associated with good outcome. No differences were found among the three techniques in terms of clinical outcome.

CONCLUSION

Stent-retrievers and a combined approach for M2 occlusions seem more effective than direct aspiration, but with higher rates of iSAH. This leads to no detectable difference in clinical outcome at 3 months.

How to Improve the Management of Acute Ischemic Stroke by Modern Technologies, Artificial Intelligence, and New Treatment Methods

Stroke remains one of the leading causes of death and disability in Europe. The European Stroke Action Plan (ESAP) defines four main targets for the years 2018 to 2030. The COVID-19 pandemic forced the use of innovative technologies and created pressure to improve internet networks. Moreover, 5G internet network will be helpful for the transfer and collecting of extremely big databases. Nowadays, the speed of internet connection is a limiting factor for robotic systems, which can be controlled and commanded potentially from various places in the world. Innovative technologies can be implemented for acute stroke patient management soon. Artificial intelligence (AI) and robotics are used increasingly often without the exception of medicine. Their implementation can be achieved in every level of stroke care. In this article, all steps of stroke health care processes are discussed in terms of how to improve them (including prehospital diagnosis, consultation, transfer of the patient, diagnosis, techniques of the treatment as well as rehabilitation and usage of AI). New ethical problems have also been discovered. Everything must be aligned to the concept of “time is brain”.

First-line contact aspiration versus first-line stent retriever for acute posterior circulation strokes: an updated meta-analysis

BACKGROUND

Both stent retriever (SR) and contact aspiration (CA) are widely used as first-line strategies for acute posterior circulation strokes (PCS). However, it is still unclear how CA and SR compare as the first-line treatment of acute PCS. Several new studies have been published recently, so we aimed to perform an updated meta-analysis.

METHODS

The meta-analysis was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) statement. Random-effects models were performed to pool the outcomes and the value of I² was calculated to assess the heterogeneity.

RESULTS

Ten observational studies with 1189 patients were included, among whom 492 received first-line CA and 697 received first-line SR. The pooled results revealed that first-line CA could achieve a significantly higher proportion of modified Thrombolysis In Cerebral Infarction (mTICI) 2b/3 (OR 1.90, 95% CI 1.33 to 2.71, I²=0%), mTICI 3 (OR 1.95, 95% CI 1.15 to 3.31, I²=59.6%), first-pass effect (OR 2.91, 95% CI 1.51 to 5.58, I²=0%), lower incidence of new-territory embolic events (OR 0.20, 95% CI 0.05 to 0.83, I²=0%), and shorter procedure time (mean difference -29.4 min, 95% CI -46.8 to -12.0 min, I²=62.8%) compared with first-line SR. At 90-day follow-up, patients subjected to first-line CA showed a higher functional independence (modified Rankin Scale score 0-2; OR 1.38, 95% CI 1.01 to 1.87, I²=23.5%) and a lower mortality (OR 0.71, 95% CI 0.50 to 1.00, p=0.050, I²=0%) than those subjected to first-line SR.

CONCLUSIONS

This meta-analysis suggests that the first-line CA strategy could achieve better recanalization and clinical outcomes for acute PCS than first-line SR. Limited by the quality of included studies, this conclusion should be drawn with caution.

Clot imaging characteristics predict first pass effect of aspiration-first approach to thrombectomy

BACKGROUND

The value of clot imaging in patients with emergent large vessel occlusion (ELVO) treated with thrombectomy is unknown.

METHODS

We performed retrospective analysis of clot imaging (clot density, perviousness, length, diameter, distance to the internal carotid artery (ICA) terminus and angle of interaction (AOI) between clot and the aspiration catheter) of consecutive cases of middle cerebral artery (MCA) occlusion and its association with first pass effect (FPE, TICI 2c-3 after a first attempt).

RESULTS

Patients (n = 90 total) with FPE had shorter clot length (9.9 ± 4.5 mm vs. 11.7 ± 4.6 mm, P = 0.07), shorter distance from ICA terminus (11.0 ± 7.1 mm vs. 14.7 ± 9.8 mm, P = 0.048), higher perviousness (39.39 ± 29.5 vs 25.43 ± 17.6, P = 0.006) and larger AOI (153.6 ± 17.6 vs 140.3 ± 23.5, P = 0.004) compared to no-FPE patients. In multivariate analysis, distance from ICA terminus to clot ≤13.5 mm (odds ratio (OR) 11.05, 95% confidence interval (CI) 2.65-46.15, P = 0.001), clot length ≤9.9 mm (OR 7.34; 95% CI 1.8-29.96, P = 0.005), perviousness ≥ 19.9 (OR 2.54, 95% CI 0.84-7.6, P = 0.09) and AOI ≥ 137°^ (OR 6.8, 95% CI 1.55-29.8, P = 0.011) were independent predictors of FPE. The optimal cut off derived using Youden's index was 6.5. The area under the curve of a score predictive of FPE success was 0.816 (0.728-0.904, P < 0.001). In a validation cohort (n = 30), sensitivity, specificity, positive and negative predictive value of a score of 6-10 were 72.7%, 73.6%, 61.5% and 82.3%.

CONCLUSIONS

Clot imaging predicts the likelihood of achieving FPE in patients with MCA ELVO treated with the aspiration-first approach.

Intraprocedural Angiographic Signs Observed During Endovascular Thrombectomy in Patients With Acute Ischemic Stroke: A Systematic Review

OBJECTIVE

In the real-world practice of endovascular thrombectomy (EVT) for acute ischemic stroke (AIS), the analysis of intraprocedural angiographic signs (IPASs) still challenges neurointerventionists. This review provides insights into the significance of these subtle changes for predicting underlying etiology, technical feasibility, and patient prognosis, thus promoting the potential real-time application of these signs.

METHODS

A systematic literature search was conducted using PubMed, Ovid Medline/Embase, and Cochrane. The search focused on studies published between January 1995 and August 2020 that reported findings related to intraprocedural angiographic manifestations in endovascular recanalization therapy for AIS.

RESULTS

We identified 12 IPASs in 22 studies involving 1,683 patients. The IPASs were assigned into 3 subsets according to their clinical meanings.

CONCLUSION

The systematic analysis of IPAS in clinical trials and practice will lead to a better understanding of treatment effects, responses, and mechanisms during EVT. Studies of larger cohorts using more robust statistical methods are needed.

Catheter tip distensibility substantially influences the aspiration force of thrombectomy devices

BACKGROUND

A direct aspiration first pass thrombectomy (ADAPT) is a fast-growing technique for which a broad catalog of catheters that provide a wide range of aspiration forces can be used. We aimed to characterize different catheters' aspiration performance on stiff clots in an in vitro vascular model. We hypothesized that labeled catheter inner diameter (labeled-ID) is not the only parameter that affects the aspiration force (asp-F) and that thrombus-catheter tip interaction and distensibility also play a major role.

METHODS

We designed an experimental setup consisting of a 3D-printed carotid artery immersed in a water deposit. We measured asp-F and distensibility of catheter tips when performing ADAPT on a stiff clot analog larger than catheter labeled-ID. Correlations between asp-F, catheter ID, and tip distensibility were statistically assessed.

RESULTS

Experimental asp-F and catheter labeled-ID were correlated (r=0.9601; P<0.01). The relative difference between experimental and theoretical asp-F (obtained by the product of the tip's section area by the vacuum pressure) correlated with tip's distensibility (r=0.9050; P<0.01), evidencing that ADAPT performance is highly influenced by catheter tip shape-adaptability to the clot and that the effective ID (eff-ID) may differ from the labeled-ID specified by manufacturers. Eff-ID showed the highest correlation with experimental asp-F (r=0.9944; P<0.01), confirming that eff-ID rather than labeled-ID should be considered to better estimate the device efficiency.

CONCLUSIONS

Catheter tip distensibility can induce a significant impact on ADAPT performance when retrieving a stiff clot larger than the device ID. Our findings might contribute to optimizing thrombectomy strategies and the design of novel aspiration catheters.

A Patient with a Delayed Diagnosis of Artery of Percheron Occlusion in Whom Thrombectomy Was Effective

Objective

A case of posterior cerebral artery (P1 segment) occlusion with consciousness disturbance and Weber's syndrome treated by mechanical thrombectomy is reported.

Case Presentation

The patient was a 69-year-old man with consciousness disturbance, left hemiparesis, and anisocoria. MRI revealed acute cerebral infarction in the midbrain and right thalamus. Angiography demonstrated that the right P1 segment was occluded and mechanical thrombectomy was performed. The right P1 segment and its perforator artery, the artery of Percheron (AOP), were both recanalized after the treatment, and the symptoms of perforator occlusion significantly improved.

Conclusion

Mechanical thrombectomy for P1 segment occlusion may be effective for improving the symptoms caused by occlusion of its perforator, the AOP.

Endovascular Management of Intracranial Atherosclerosis-Related Large Vessel Occlusion With the A Direct Aspiration First-Pass Thrombectomy Compared With Solumbra Technique

Background: To investigate the effect of the A Direct Aspiration First-Pass Thrombectomy (ADAPT) vs. Solumbra technique in the treatment of acute intracranial atherosclerosis-related large vessel occlusion (LVO).

Methods: Patients with acute atherosclerosis-related LVO who had undergone endovascular treatment were retrospectively enrolled into two groups: The Solumbra and ADAPT groups. The clinical data were analyzed.

Results: Patients (104) were enrolled with 48 in the Solumbra and 56 in the ADAPT group. The mean time from femoral access to recanalization was significantly (P < 0.05) shorter in the ADAPT than in the Solumbra group. The recanalization time at the first line was significantly shorter in the ADAPT group than in the Solumbra group (17 ± 10.21 vs. 26 ± 15.55 min, P = 0.02). However, the rate of switching to the alternative was significantly higher in the ADAPT group than that in the Solumbra group (46.42 vs. 33.33%, P = 0.01). Eighty-two patients had eventual recanalization, resulting in a final recanalization rate of 78.85%. At 3-month clinical follow-up for all patients, the good prognosis rate reached 51.92% with good prognosis in 24 patients (50%) in the Solumbra and 30 (53.57%) in the ADAPT group. The rate of symptomatic intracranial hemorrhage was 18.75% (n = 9) in the Solumbra and 19.64% (n = 11) in the ADAPT group. The mortality rate was 21.15% (22/104). Among 80 (76.92%) patients who had angiographic follow-up (3–30 months), five (6.25%) patients experienced in-stent stenosis, and two (2.5%) experienced asymptomatic stent occlusion.

Conclusion: In patients with acute intracranial atherosclerosis-related LVO, clinical outcomes treated using the ADAPT technique are comparable with those using the Solumbra technique, and more patients need additional remedial measures if treated with the ADAPT technique.

MRS SOFIA: a multicenter retrospective study for use of Sofia for revascularization of acute ischemic stroke

BACKGROUND

Over the past several years there has been increased interest in the use of the Sofia aspiration system (MicroVention, Tustin, California) as a primary aspiration catheter.

OBJECTIVE

To perform a multicenter retrospective study examining the efficacy of the Sofia aspiration catheter as a standalone aspiration treatment for large vessel occlusion.

METHODS

Consecutive cases in which the Sofia catheter was used for aspiration thrombectomy for large vessel occlusion were included. Exclusion criteria were the following: (1) Sofia not used for first pass, and (2) a stent retriever used as an adjunct on the first pass. The primary outcome of the study was first pass recanalization (Thrombolysis in Cerebral Infarction (TICI) 2c/3). Secondary outcomes included first pass TICI 2b/3, crossover to other thrombectomy devices, number of passes, time from puncture to recanalization, and complications.

RESULTS

323 patients were included. First pass TICI 2c/3 was achieved in 49.8% of cases (161/323). First pass TICI 2b/3 was achieved in 69.7% (225/323) of cases. 74.8% had TICI 2b/3 with the Sofia alone. Crossover to other thrombectomy devices occurred in 29.1% of cases (94/323). The median number of passes was 1 (IQR=1-3). Median time from puncture to recanalization was 26 min (IQR=17-45). Procedure related complications occurred in 3.1% (10/323) of cases.

CONCLUSION

Our study highlights the potential advantage of the Sofia aspiration catheter for primary aspiration thrombectomy in acute ischemic stroke. High rates of first pass recanalization with low crossover rates to other thrombectomy devices were achieved. Median procedure time was low, as were procedural complications.

Experimental evaluation of direct thromboaspiration efficacy according to the angle of interaction between the aspiration catheter and the clot

Background

Successful direct thromboaspiration (DTA) is related to several factors such as clot consistency, size, and location. It has also been demonstrated recently that the angle of interaction (AOI) formed by the aspiration catheter and the clot is related to DTA efficacy. The aims of this study were three-fold: (a) to confirm the clinical finding that the AOI formed by the aspiration catheter and the clot influence DTA efficacy; (b) to evaluate to what extent this influence varies according to differences in clot consistency and size; and (c) to validate stent retriever thrombectomy as an effective rescue treatment after DTA failure in the presence of an unfavorable AOI.

Methods

A rigid vascular phantom designed to reproduce a middle cerebral artery trifurcation anatomy with three M2 segments forming different angles with M1 and thrombus analog of different consistencies and sizes was used.

Results

DTA was highly effective for AOIs >125.5°, irrespective of thrombus analog features. However, its efficacy decreased for acute AOIs. Rescue stent retriever thrombectomy was effective in 92.6% of cases of DTA failure.

Conclusions

This in vitro study confirmed that the AOI formed by the aspiration catheter and the thrombus analog influenced DTA efficacy, with an AOI >125.5° related to an effective DTA. Stent retriever thrombectomy was an effective rescue treatment after DTA failure, even in the presence of an unfavorable AOI.

Systematic review and meta-analysis of current rates of first pass effect by thrombectomy technique and associations with clinical outcomes

BACKGROUND

First pass effect (FPE) in mechanical thrombectomy is thought to be associated with good clinical outcomes.

OBJECTIVE

To determine FPE rates as a function of thrombectomy technique and to compare clinical outcomes between patients with and without FPE.

METHODS

In July 2020, a literature search on FPE (defined as modified Thrombolysis in Cerebral Infarction (TICI) 2c-3 after a single pass) and modified FPE (mFPE, defined as TICI 2b-3 after a single pass) and mechanical thrombectomy for stroke was performed. Using a random-effects meta-analysis, we evaluated the following outcomes for both FPE and mFPE: overall rates, rates by thrombectomy technique, rates of good neurologic outcome (modified Rankin Scale score ≤2 at day 90), mortality, and symptomatic intracerebral hemorrhage (sICH) rate.

RESULTS

Sixty-seven studies comprising 16 870 patients were included. Overall rates of FPE and mFPE were 28% and 45%, respectively. Thrombectomy techniques shared similar FPE (p=0.17) and mFPE (p=0.20) rates. Higher odds of good neurologic outcome were found when we compared FPE with non-FPE (56% vs 41%, OR=1.78) and mFPE with non-mFPE (57% vs 44%, OR=1.73). FPE had a lower mortality rate (17% vs 25%, OR=0.62) than non-FPE. FPE and mFPE were not associated with lower sICH rate compared with non-FPE and non-mFPE (4% vs 18%, OR=0.41 for FPE; 5% vs 7%, OR=0.98 for mFPE).

CONCLUSIONS

Our findings suggest that approximately one-third of patients achieve FPE and around half of patients achieve mFPE, with equivalent results throughout thrombectomy techniques. FPE and mFPE are associated with better clinical outcomes.

Increased Perviousness on CT for Acute Ischemic Stroke is Associated with Fibrin/Platelet-Rich Clots

BACKGROUND AND PURPOSE

Clot perviousness in acute ischemic stroke is a potential CT imaging biomarker for mechanical thrombectomy efficacy. We investigated the association among perviousness, clot cellular composition, and first-pass effect.

MATERIALS AND METHODS

In 40 mechanical thrombectomy-treated cases of acute ischemic stroke, we calculated perviousness as the difference in clot density on CT angiography and noncontrast CT. We assessed the proportion of fibrin/platelet aggregates, red blood cells, and white blood cells on clot histopathology. We tested for linear correlation between histologic components and perviousness, differences in components between "high" and "low" pervious clots defined by median perviousness, and differences in perviousness/composition between cases that did and did not achieve a first-pass effect.

RESULTS

Perviousness significantly positively and negatively correlated with the percentage of fibrin/platelet aggregates (P = .001) and the percentage of red blood cells (P = .001), respectively. Higher pervious clots had significantly greater fibrin/platelet aggregate content (P = .042). Cases that achieved a first-pass effect (n = 14) had lower perviousness, though not significantly (P = .055). The percentage of red blood cells was significantly higher (P = .028) and the percentage of fibrin/platelet aggregates was significantly lower (P = .016) in cases with a first-pass effect. There was no association between clot density on NCCT and clot composition or first-pass effect. Receiver operating characteristic analysis indicated that clot composition was the best predictor of first-pass effect (area under receiver operating characteristic curve: percentage of fibrin/platelet aggregates  = 0.731, percentage of red blood cells  = 0.706, perviousness = 0.668).

CONCLUSIONS

Clot perviousness on CT is associated with a higher percentage of fibrin/platelet aggregate content. Histologic data and, to a lesser degree, perviousness may have value in predicting first-pass outcome. Imaging metrics that more strongly reflect clot biology than perviousness may be needed to predict a first-pass effect with high accuracy.

Effect of manual aspiration thrombectomy using large-bore aspiration catheter for acute basilar artery occlusion: comparison with a stent retriever system

Background

A large-bore aspiration catheter can be employed for recanalization of acute basilar artery occlusion. Here we compare the results of mechanical thrombectomy using a stent retriever (SR) and manual aspiration thrombectomy (MAT) using a large-bore aspiration catheter system as a first-line recanalization method in acute basilar artery occlusion (BAO).

Methods

The records of 50 patients with acute BAO who underwent mechanical thrombectomy were retrospectively reviewed. Patients were assigned to one of two groups based on the first-line recanalization method. The treatment and clinical outcomes were compared.

Results

Sixteen (32%) patients were treated with MAT with a large-bore aspiration catheter and 34 (68%) with a SR as the first-line treatment method. The MAT group had a shorter procedure time (28 vs. 65 min; p = 0.001), higher rate of first-pass recanalization (68.8% vs. 38.2%, p = 0.044), and lower median number of passes (1 vs 2; p = 0.008) when compared with the SR group. There was no significant difference in the incidence of any hemorrhagic complication (6.3% vs. 8.8%; p = 0.754) between the groups. However, there were four cases of procedure-related subarachnoid hemorrhage (SAH) in the SR group and one death occurred due to massive hemorrhage.

Conclusions

Selection of MAT using a large-bore aspiration catheter for acute BAO may be a safe and effective first-line treatment method with higher first-pass recanalization rate and shorter procedure time than SR.

Endovascular treatment of acute ischemic stroke

Endovascular treatment of acute ischemic stroke has become the first choice of treatment in large cerebral vessel occlusions, with a very high efficacy in terms of revascularization and reducing disability of affected patients. Revolutionizing acute therapy, it induced important paradigm shifts in the concepts of time and salvageable brain. In this review we focus on the current concepts of patient selection, imaging, techniques and perspectives of endovascular stroke treatment.