Maximizing First-Pass Complete Reperfusion with SAVE

Evaluation of partial resheathing of EmboTrap III using the microcatheter (PREMIER) technique for fibrin-rich hard clots in an in vitro vessel model

Background and purpose

Despite the ongoing advancements in mechanical thrombectomy for large vessel occlusions causing acute ischemic stroke, successful recanalization is not achieved in all patients. One contributing factor is the presence of fibrin-rich hard clots. We proposed a new technique called the PREMIER technique, which aims to retrieve fibrin-rich clots. This study evaluated the efficacy of the PREMIER technique on fibrin-rich and erythrocyte-rich clots by comparing it with the simple use of EmboTrap III in an in vitro vessel model.

Methods

The PREMIER technique involves partially resheathing a fully deployed EmboTrap III (CERENOVUS, Johnson & Johnson Medical Devices, Irvine, California, USA) using a microcatheter to capture and retrieve a hard clot between the inner channel and outer cages of EmboTrap III. We compared recanalization rate of the PREMIER technique with the simple use of EmboTrap III in an in vitro vessel model, occluding the M1 segment with fibrin-rich hard clots (0% erythrocyte composition) and erythrocyte-rich clots (50% erythrocyte composition).

Results

Among the 40 procedures (10 each for the PREMIER technique and the simple use of EmboTrap III for two different clots) for fibrin-rich clots, the PREMIER technique achieved successful recanalization in all 10 cases, with a significantly higher recanalization rate than the EmboTrap III (100% vs. 50%, p = 0.03). For erythrocyte-rich clots, the recanalization rate was not significantly different in the PREMIER technique compared with the simple use of EmboTrap III (80% vs. 70%, p = 1.00).

Conclusion

The PREMIER technique is a novel technique for acute large-vessel occlusions caused by fibrin-rich hard clots that hinders successful recanalization during mechanical thrombectomy.

Optimal Catheter Selection for Patients with Acute Stroke with Type III Aortic Arch Based on Magnetic Resonance Angiography Road Mapping of the Para-Aortic Transfemoral Access Route Before Mechanical Thrombectomy

BACKGROUND

Although mechanical thrombectomy for acute ischemic stroke has a high recanalization rate, procedurally challenging lesions remain in approximately 10% of the cases. Type III aortic arches, due to their anatomical configuration, are a fundamental problem impacting this procedure. This study aimed to determine whether optimal catheter selection for type III aortic arches, using magnetic resonance angiography (MRA)-based road mapping of the para-aortic transfemoral access route, reduces the time required for mechanical thrombectomy.

METHODS

We retrospectively evaluated 203 consecutive patients who underwent mechanical thrombectomy at multiple centers between April 2018 and July 2022. 23 patients were diagnosed with a type III aortic arch using MRA-based road mapping performed to visualize the para-aortic access route before neuro-interventional procedures. Among the 23 patients with type III aortic arches, 10 received a Simmons-type catheter (initial Simmons group) and 13 received a JB-2-type catheter (initial JB-2 group) as their first inner catheter. The time required for mechanical thrombectomy was compared between the groups.

RESULTS

Compared with the initial JB-2 group, the initial Simmons group exhibited a significantly shorter "puncture-to-recanalization time" (105 vs. 53 minutes, P = 0.009) and "door-to-recanalization time" (164 vs. 129 minutes, P = 0.032).

CONCLUSIONS

Optimal catheter selection by identifying the aortic arch before mechanical thrombectomy using MRA-based road mapping effectively reduced the mechanical thrombectomy time. This suggests that even in type III aorta cases, appropriate catheter selection may shorten the mechanical thrombectomy time and improve acute ischemic stroke prognosis.

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.

Initial experience with a novel stent-based mechanical thrombectomy device for management of acute myocardial infarction cases with large thrombus burden

BACKGROUND

Patients with acute myocardial infarction (AMI) and large thrombus burden (LTB) still represent a challenge. Afflicted patients have a high morbidity and mortality. Aspiration thrombectomy is often ineffective in those cases. Mechanical thrombectomy devices (MTDs), which are effective for management of ischemic strokes, were recently CE-approved for treatment of thrombotic coronary lesions. Real-world data about their performance in AMI cases with LTB are scarce. This study sought to summarize our early experience with a novel MTD device in this context.

METHODS

We analyzed consecutive patients from the prospective OPTIMISER registry (NCT04988672), who have been managed with the NeVa™ MTD (Vesalio, USA) for AMI with LTB at a tertiary cardiology facility. Outcomes of interest included, among others, periprocedural complications, target lesion failure (TLF), target lesion revascularization (TLR) and target vessel myocardial infarction (TV-MI).

RESULTS

Overall, 15 patients underwent thrombectomy with the NeVa™ device. Thrombectomy was successfully performed in 14 (93%) patients. Final TIMI 3 flow was achieved in 13 (87%) patients, while 2 (13%) patients had TIMI 2 flow. We encountered no relevant periprocedural complications, especially no stroke, stent thrombosis or vessel closure. After a mean follow-up time of 26 ± 2.9 months, 1 (7%) patient presented with TLR due to stent thrombosis (10 months after treatment with the MTD and stenting).

CONCLUSIONS

In AMI patients with LTB, the deployment of the novel NeVa™ MTD seems efficient and safe. Further randomized trials are warranted to assess whether the use of the NeVa™ device in cases with LTB improves procedural and clinical outcomes.

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.

Efficacy and safety of combined stent retriever and contact aspiration vs. stent retriever alone on revascularization in patients with acute ischemic stroke: a systematic review and meta-analysis

Objective

Whether the efficacy of combined stent retriever and contact aspiration (S + A) is superior to stent retriever (S) alone for revascularisation in patients with large vessel occlusive stroke remains uncertain. The aim of this meta-analysis was to assess the safety and efficacy of combined stent retriever and contact aspiration for the treatment of acute ischaemic stroke with large vessel occlusion by comparing it with stent retriever alone.

Methods

We systematically searched the PubMed, Embase, Web of Science, and The Cochrane Library databases for randomised controlled trials and observational studies (case-control and cohort studies) published before 1 October 2023 comparing the efficacy of combined stent retriever and contact aspiration versus tent retriever alone in patients with large vessel occlusive stroke. The end point of the primary efficacy observed in this meta-analysis study was the rate of first pass nearly complete or complete recanalisation (mTICI 2c-3). Secondary effectiveness nodes were: rate of first pass successful recanalisation (mTICI 2b-3), rate of near-complete or complete recanalisation of the postoperative vessel, rate of successful recanalisation of the postoperative vessel, and MRS 0-2 within 90 days. Safety endpoints were interoperative embolism, symptomatic intracranial haemorrhage, and mortality within 90 days.

Results

A total of 16 studies were included in the literature for this meta-analysis, with a total of 7,320 patients (S + C group: 3,406, S group: 3,914). A comprehensive analysis of the included literature showed that combined stent retriever and contact aspiration had a higher rate of near-complete or complete recanalisation of the postoperative vessel [OR = 1.53, 95% CI (1.24, 1.88), p < 0.0001] and rate of successful recanalisation of the postoperative vessel compared to stent retriever alone [OR = 1.83, 95% CI (1.55, 2.17), p < 0.00001]; there were no statistically significant differences between the two groups in terms of the rate of first pass nearly complete or complete recanalisation [OR = 1.00, 95% CI (0.83, 1.19), p = 0.96], rate of first pass successful recanalisation [OR = 1.02, 95% CI (0.85, 1.24), p = 0.81], interoperative embolism [OR = 0.93, 95% CI (0.72, 1.20), p = 0.56], symptomatic intracranial haemorrhage [OR = 1.14, 95% CI (0.87, 1.48), p = 0.33], MRS 0-2 within 90 days [OR = 0.89, 95% CI (0.76, 1.04), p = 0.14] and mortality within 90 days [OR = 1.11, 95% CI (0.94, 1.31), p = 0.22].

Conclusion

Combined stent retriever and contact aspiration has a higher rate of postprocedural revascularisation (mTICI 2c-3/mTICI 2b-3) compared with stent retriever alone in patients with large vessel occlusion stroke. In addition, it was not superior to stenting alone in terms of the rate of first pass recanalisation (mTICI 2c-3/mTICI 2b-3), interoperative embolisation, symptomatic intracranial haemorrhage, good functional prognosis within 90 days and mortality within 90 days.

Mechanical thrombectomy using the Nimbus stent-retriever - initial experiences in a single-center observational study

BACKGROUND

The Nimbus stent-retriever (NSR) was developed for mechanical thrombectomy of wall-adherent thrombi in cerebral arteries. It features a novel geometry with a proximal spiral section and a distal barrel section. The new device is designed to retrieve tough clots with a micro-clamping technique. In the first case series reporting on the NSR, we share our initial experience about the first 12 treated cases.

METHODS

In total, 12 patients (5 men, 7 women; mean age 78 years) with occlusion of the internal carotid artery or the middle cerebral artery (M1 or M2 segment) were treated with the NSR, 11 after unsuccessful recanalization attempts with conventional stent-retrievers or aspiration thrombectomy.

RESULTS

Retrieving maneuvers with the NSR recovered a thrombus in 7 patients (58%), of which 6 resulted in vessel recanalization mTICI ≥ 2b. Successful recanalization improved the mTICI score by a median of 3 points. In 5 of 7 cases, this required only one thrombectomy maneuver. In 5 cases, no improvement of recanalization could be achieved with the NSR (1-3 attempts). No NSR-related complications occurred in this case series.

CONCLUSIONS

In our initial experience, the NSR appeared to be a safe and effective second-line stent-retriever after unsuccessful MT with conventional stent-retrievers or aspiration thrombectomy allowing for mTICI ≥ 2b rescue thrombectomy in ab 50% of cases. No NSR associated complications occurred in our case series.

Nimodipine as Vasodilator in Guide Catheter Flush to Prevent Vasospasm During Endovascular Stroke Treatment

PURPOSE

The clinical importance and management of vasospasm as a complication during endovascular stroke treatment (EVT) has not been well studied. We sought to investigate the effect of adding nimodipine to the guiding catheter flush (GCF) to prevent vasospasm during EVT.

METHODS

This is a single-center retrospective analysis including patients with EVT (stent-retriever and/or distal aspiration) treated for anterior or posterior circulation intracranial vessel occlusion from January 2018 to June 2023. Exclusion criteria were intracranial or extracranial stenosis, intra-arterial alteplase, patient age over 80 years. Study groups were patients with (nimo+) and without (nimo-) nimodipine in the GCF. They were compared for occurrence of vasospasm as primary endpoint and clinical outcome in univariate analysis.

RESULTS

477 patients were included in the analysis (nimo+ n = 94 vs. nimo- n = 383). Nimo+ patients experienced less vasospasm during EVT (e.g. vasospasm in target vessel n (%): nimo- = 113 (29.6) vs. nimo+ = 9 (9.6), p < 0.001; extracranial vasospasm, n (%): nimo- = 68 (17.8) vs. nimo+ = 7 (7.4), p = 0.017). Patients of the two study groups had a comparable clinical outcome (90 day mRS, median (IQR): 3 (1-6) for both groups, p = 0.896). In general, patients with anterior circulation target vessel occlusion (TVO) experienced more vasospasm (anterior circ. TVO 38.7% vs. posterior circ. 7.5%, p = 0.006).

CONCLUSION

Prophylactic adding of nimodipine reduces the risk of vasospasm during EVT without affecting the clinical outcome. Patients with anterior circulation TVO experienced more vasospasm compared to posterior circulation TVO.

The pEGASUS-HPC stent system for intracranial arterial stenosis: a single-center case series

BACKGROUND

Intracranial arterial stenting is a technique for the treatment of symptomatic stenosis. In this single-center retrospective case series we evaluated a novel low profile laser-cut stent with an antithrombogenic hydrophilic polymer coating (pEGASUS-HPC, Phenox GmbH, Bochum, Germany) for the treatment of intracranial stenosis in the setting of acute ischemic stroke and elective cases.

METHODS

All patients treated with pEGASUS-HPC for one or more intracranial arterial stenoses at our institution were retrospectively included. Clinical, imaging and procedural parameters as well as clinical and imaging follow-up data were collected.

RESULTS

We performed 43 interventions in 41 patients with 42 stenoses in our neurovascular center between August 2021 and February 2024. Twenty-one patients (51.2%) were female and the mean±SD age was 71±10.8 years. Thirty-seven (86.1%) procedures were performed in the setting of endovascular acute ischemic stroke treatment. Technical or procedural complications occurred in seven patients (16.3%), six in the thrombectomy group and one in the elective group. One stent-related hemorrhagic complication (subarachnoid hemorrhage) occurred in emergency cases and symptomatic intracerebral hemorrhage occurred in one patient treated in an elective setting. Overall stenosis reduction following pEGASUS-HPC stent implantation was 53.0±18.0%. On follow-up imaging, which was available for 16 patients (37.2%) after an average of 32±58.6 days, 62.5% of the stents were patent.

CONCLUSION

Our single-center case series demonstrates the feasibility of using the pEGASUS-HPC stent system, especially in emergency situations when thrombectomy fails.

Prospective evaluation to characterize the real-world performance of the EMBOVAC aspiration catheter for neurothrombectomy: a post-market clinical follow-up trial

BACKGROUND

A direct aspiration first pass technique (ADAPT) is an effective alternative to stent retriever thrombectomy for patients with large vessel occlusion (LVO). The PERFECT study evaluated direct aspiration with the EMBOVAC large bore aspiration catheter in patients with LVO strokes.

METHODS

PERFECT was a prospective, post-market, single-arm, multicenter, observational study of patients enrolled across 11 European centers between October 2020 and July 2022. Three direct aspiration passes with EMBOVAC were mandated before switching strategy. The primary endpoint was core-lab assessed successful reperfusion (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2b) post-procedure. Other outcomes included first pass mTICI ≥2c, independent 90-day modified Rankin Scale (mRS) evaluation, and symptomatic intracerebral hemorrhage (sICH) at 24 hours by a clinical events committee.

RESULTS

EMBOVAC was used in 100 patients (mean age 70.4±14.0 years, 59.0% (59/100) female). Final mTICI ≥2b was achieved in 98.0% (97/99), final mTICI ≥2b with no change in frontline therapy or thrombolytics use during the procedure was achieved in 87.9% (87/99), final mTICI ≥2c in 86.9% (86/99), and first pass mTICI ≥2c in 53.5% (53/99). sICH at 24 hours was 0%. The 90-day mRS ≤2 rate was 56.6% (56/99) and all-cause mortality was 12.9%. One device-related serious adverse event occurred within 90 days (1.0%).

CONCLUSIONS

PERFECT demonstrates that EMBOVAC achieves successful reperfusion rates and favorable clinical outcomes when used in the endovascular treatment of acute ischemic stroke (AIS) using a direct aspiration technique as first line therapy in a real-world setting in patients with AIS secondary to large vessel occlusion.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov Unique identifier: NCT04531904.

Fubuki XF Long Sheath guide catheter use in neuroendovascular procedures: Institutional experience in 60 cases

BACKGROUND

Endovascular treatment devices require compatible guide catheters to navigate complex vessels and anatomy. The Fubuki XF Long Sheath guide catheter (Fubuki XF) was developed with a 0.090-inch internal diameter with hydrophilic coating, an atraumatic rounded tip, and enhanced trackability and support with gradual shaft transition zones.

METHODS

We retrospectively analyzed a prospectively maintained database of neuroendovascular patients treated using Fubuki XF at our center (July 2022─May 2023). Baseline/procedural characteristics were collected. Outcomes of interest included technical success (procedure completion with Fubuki XF without alternative guide catheter use) and peri-procedural complications.

RESULTS

This study included 60 patients (43.3% [26/60] female; mean age: 69.6 ± 9.7) presenting with stenosis (45.0% [27/60]), unruptured aneurysms (31.7% [19/60]), ruptured aneurysm (1.7% [1/60]), arteriovenous fistula (5.0% [3/60]), arteriovenous malformation (3.3% [2/60]), chronic subdural hematoma (3.3% [2/60]), stroke/emboli (6.7% [4/60]), vasospasm (1.7% [1/60]), or carotid web (5.0% [1/60]). Fubuki XF was used to deliver endovascular treatment devices for stenting (43.3% [26/60]), flow diversion (23.3% [14/60]), embolization (11.7% [7/60]), coiling (10.0% [6/60]), balloon angioplasty (10.0% [6/60]), and mechanical thrombectomy (1.7% [1/60]). The Fubuki XF tip was placed in the internal carotid artery in 38.3% (23/60) of cases. Technical success was achieved in all cases. One V1 non-flow-limiting dissection (not related to Fubuki XF) and one failed closure occurred (1.7% [1/60] each). No iatrogenic strokes or intraprocedural ruptures occurred.

CONCLUSION

We used Fubuki XF to safely and effectively deliver a variety of compatible neuroendovascular devices. Fubuki XF was stable in all cases and locations, and there were no device-related complications or dissections.

Mechanical Thrombectomy in Stroke-Retrospective Comparison of Methods: Aspiration vs. Stent Retrievers vs. Combined Method-Is Aspiration the Best Starting Point?

Background: There are three main methods of mechanical thrombectomy (MT): using a stent retriever (SR) only (SO), aspiration catheter (AC) only (AO) and the combined method (CM) using both the SR and AC. This paper describes a real-life, single-center experience using SO, AO and CM during 276 consecutive MTs. Methods: The primary endpoint was the frequency of first-pass complete (FPE TICI3). The secondary endpoints were final mTICI 2b-3, procedure duration, clinical outcome and the total number of device passes. The third aim of this study was to test the association between the clinical outcomes in patients treated with each method and various factors. Results: There was a significant difference (p = 0.016) between the groups' FPE TICI3 rates with 46% mTICI 3 in the AO group, 41% in the CM group and 21% in the SO group. AO resulted in procedure time shortening to a mean duration of 43 min, and the scores were 56 min for CM and 63 min for SO (p < 0.0001). There were no significant differences in clinical outcomes or in-hospital mortality. The analysis showed a correlation between good clinical outcomes and the administration of IVT: OR 1.71 (1.03-2.84) p = 0.039. Patients ≥66 years old had higher odds of a bad outcome compared to younger patients in general (OR, 1.99 95% CI, 1.17-3.38; p = 0.011). FPE TICI3 was associated with good functional outcomes in the whole treated cohort (OR, 1.98; 95% CI, 1.21-3.25; p = 0.006). Conclusions: In our series, AO proved to be the best starting point in most cases. It demonstrates good technical efficacy regarding FPE, it is fast and clinical outcomes seem to be the least age- and FPE TICI3-dependent. It can be easily converted into the combined method, which had the second-best outcomes in our cohort.

"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.

The proximal balloon occlusion together with direct thrombus aspiration (protect plus) technique: Experience at a tertiary comprehensive stroke center

BACKGROUND

Timely restoration of cerebral blood flow using reperfusion therapy is the most effective maneuver for salvaging penumbra. We re-evaluated the previously described PROTECT (PRoximal balloon Occlusion TogEther with direCt Thrombus aspiration during stent retriever thrombectomy) Plus technique at a tertiary comprehensive stroke center.

METHODS

We retrospectively analyzed all patients who underwent mechanical thrombectomy with stentrievers between May 2011 and April 2020. Patients were divided between those who underwent PROTECT Plus and those who did not (proximal balloon occlusion with stent retriever only). We compared the groups in terms of reperfusion, groin to reperfusion time, symptomatic intracranial hemorrhage (sICH), modified Rankin Scale (mRS) score at discharge.

RESULTS

Within the study period, 167 (71.4%) PROTECT Plus and 67 (28.6%) non-PROTECT patients which met our inclusion criteria. There was no statistically significant difference in the number of patients with successful reperfusion (mTICI >2b) between the techniques (85.0% vs 82.1%; p = 0.58). The PROTECT Plus group had lower rates of mRS ≤2 at discharge (40.1% vs 57.6%; p = 0.016). The rate of sICH was comparable (p = 0.35) between the PROTECT Plus group (7.2%) and the non-PROTECT group (3.0%).

CONCLUSION

The PROTECT Plus technique using a BGC, a distal reperfusion catheter and stent retriever is feasible for recanalization of large vessel occlusions. Successful recanalization, first-pass recanalization and complication rates are similar between PROTECT Plus and non-PROTECT stent retriever techniques. This study adds to an existing body of literature detailing techniques that use both a stent retriever and a distal reperfusion catheter to maximize recanalization for patients with large vessel occlusions.

Development of a clot-adhesive coating to improve the performance of thrombectomy devices

BACKGROUND

The first-pass complete recanalization by mechanical thrombectomy (MT) for the treatment of stroke remains limited due to the poor integration of the clot within current devices. Aspiration can help retrieval of the main clot but fails to prevent secondary embolism in the distal arterial territory. The dense meshes of extracellular DNA, recently described in stroke-related clots, might serve as an anchoring platform for MT devices. We aimed to evaluate the potential of a DNA-reacting surface to aid the retention of both the main clot and small fragments within the thrombectomy device to improve the potential of MT procedures.

METHODS

Device-suitable alloy samples were coated with 15 different compounds and put in contact with extracellular DNA or with human peripheral whole blood, to compare their binding to DNA versus blood elements in vitro. Clinical-grade MT devices were coated with two selected compounds and evaluated in functional bench tests to study clot retrieval efficacy and quantify distal emboli using an M1 occlusion model.

RESULTS

Binding properties of samples coated with all compounds were increased for DNA (≈3-fold) and decreased (≈5-fold) for blood elements, as compared with the bare alloy samples in vitro. Functional testing showed that surface modification with DNA-binding compounds improved clot retrieval and significantly reduced distal emboli during experimental MT of large vessel occlusion in a three-dimensional model.

CONCLUSION

Our results suggest that clot retrieval devices coated with DNA-binding compounds can considerably improve the outcome of the MT procedures in stroke 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.

Partial (SAVE) versus Complete (Solumbra) Stent Retriever Retraction Technique for Mechanical Thrombectomy: A Randomized In Vitro Study

BACKGROUND AND PURPOSE

Mechanical thrombectomy has become a first-line treatment for acute ischemic stroke. Several techniques combining stent retrievers and distal aspiration catheters have been described. We aimed to characterize the efficacy of 2 commonly used techniques according to clot characteristics.

MATERIALS AND METHODS

Soft (mean stiffness = 95.77 [SD, 5.80] kPa) or stiff (mean stiffness = 205.63 [SD, 6.70] kPa) clots (3 × 10 mm and 2 × 10 mm, respectively) were embolized to the distal M1 segment of the MCA in an in vitro model. The technique was randomly allocated (1:1): stent retriever assisted vacuum-locked extraction (SAVE) versus complete retraction (Solumbra). The primary end point was the percentage of first-pass recanalization. Secondary end points were periprocedural distal embolization measures.

RESULTS

A total of 130 mechanical thrombectomies were performed (50 for soft clots and 15 for stiff clots per arm). Overall, the rate of first-pass recanalizaton was 35% with Solumbra and 15% with SAVE (P < .01). For stiff clots, the first-pass recanalizaton was equal for both methods (27%; P = 1.00). With soft clots, the first-pass recanalizaton was higher with Solumbra (38%) than with SAVE (12%; P < .01). When we used soft clots, the maximum embolus size (mean, 1.19 [SD, 0.9] mm versus 2.16 [SD, 1.48] mm; P < .01) and total area of emboli (mean, 1.82 [SD, 2.73] versus 3.34 [SD, 3.2]; P = .01) were also lower with Solumbra than with SAVE.

CONCLUSIONS

Clot characteristics may influence the efficacy of the thrombectomy technique. In occlusions caused by soft clots, complete retrieval into the distal aspiration catheters achieved higher rates of first-pass recanalizaton and lower embolization.

Efficacy, safety, and predictors for functional outcomes of mechanical thrombectomy in patients aged over 90 years with acute ischemic stroke and literature review

BACKGROUND

No evidence supports the efficacy and safety of mechanical thrombectomy (MT) in patients aged ≥ 90 years with acute ischemic stroke (AIS). This study clarifies the efficacy, safety, and predictors of MTs in patients aged ≥ 90 years by investigating our results and reviewing previous studies.

METHODS

We retrospectively investigated data from 80 consecutive patients who underwent MT at our hospital between 2018 and 2021. We analyzed outcomes using the modified Thrombolysis in the Cerebral Infarction (mTICI) scale and modified Rankin Scale (mRS). Functional outcomes were investigated at 90 days or discharge.

RESULTS

We obtained functional outcomes mRS ≤ 3 patients in 41.6%. The mortality rate was 16.6%. The rate of successful recanalization was 75%. Comparison mRS ≤ 3 and mRS ≥ 4 at 90 days or discharge showed statistical significance in the National Institute of Health Stroke Scale, the location of occluded vessels, and mTICI ≥ 2b at the first pass. Univariable logistic regression analysis indicated that the Alberta Stroke Program Early Computed Tomography Score was a predictor of mRS ≤ 3.

CONCLUSIONS

The efficacy is lower than that of patients aged < 90; however, MT is effective even in patients aged ≥ 90 years. The safety of MT in patients aged ≥ 90 years was similar to that in those aged < 90 years. Neuro-interventionalists should consider predictors and take the best strategies to achieve successful recanalization in patients aged ≥ 90 years with AIS.

Cerebral Venous Sinus Thrombosis Successfully Treated with Mechanical Thrombectomy under Intracranial Pressure Monitoring: A Case Report

A 54-year-old man with no medical history presented to our hospital with vomiting, left hemiplegia, and seizures. On arrival, he was experiencing generalized tonic-clonic seizures, which required him to be intubated and deeply sedated. Contrast-enhanced computed tomography revealed extensive venous sinus obstruction from the superior sagittal sinus to the bilateral sigmoid sinus and cerebral edema with intracranial hemorrhage. An intracranial pressure (ICP) monitor was immediately placed intracranially, and mechanical thrombectomy (MT) was performed under ICP monitoring. MT was immediately terminated when the venous sinus was partially recanalized enough to decrease the ICP; then, anticoagulation therapy was initiated. Postoperative follow-up angiography revealed that venous sinus obstruction and intracranial venous perfusion improved over time. Although he had intracranial hemorrhage-induced left hemiplegia and sensory deficits, his condition improved with rehabilitation, and the patient was eventually discharged home. The indication criteria and techniques for MT for cerebral venous sinus thrombosis are yet to be established. As in this case, in patients with impaired consciousness due to intracranial hemorrhage or epilepsy, preoperative ICP monitor placement is deemed useful to evaluate venous perfusion during MT and decide the treatment goal.

First-Pass Effect in M1-Occlusion Stroke Patients Treated with Combined Stent-Retriever/Large-Bore Distal Aspiration Catheter Thrombectomy

INTRODUCTION

Combined stent-retriever/large-bore distal aspiration catheter (LB-DAC) thrombectomy was recently introduced to treat large-vessel occlusion; however, it is unclear whether larger inner diameters improve outcomes. We compared angiographic and clinical outcomes in patients with occlusions of the M1 segment of the middle cerebral artery treated with mechanical thrombectomy using extra-LB-DAC versus LB-DAC in combination with stent-retrievers.

METHODS

We analyzed consecutive patients with M1 occlusion included in the ROSSETTI registry treated with non-balloon guide catheter combined LB-DAC/stent-retriever thrombectomy between June 2019 and April 2022. We compared demographics, baseline clinical variables, procedural variables, angiographic outcomes, and clinical outcomes [National Institute of Health Stroke Scale score at 24 h (24h-NIHSS) and modified Rankin scale score at 3 months] between patients treated with extra-LB-DAC (Sofia Plus, MIVI Q6, Catalyst7; inner diameter, 0.068″-0.070″) versus LB-DAC (Sofia 5F, MIVI Q5, Catalyst 6; inner diameter, 0.055″-0.064″). Primary outcome was the first-pass effect (FPE) rate, defined as near-complete/complete reperfusion (mTICI 2c-3) after a single pass of the device.

RESULTS

We included 324 patients (extra-LB-DAC, 185, 57.1% patients). Demographics, clinical data, and clinical outcomes were similar between the two groups; however, there was a trend towards improvement in National Institute of Health Stroke Scale score at 24 h (24h-NIHSS) in the cohort treated with extra-LB-DAC 9 points (IQR 4;16 points) vs. 12 points (IQR 4;18 points, P = 0.083). Patients treated with extra-LB-DAC had higher FPE rate (47% vs. 30.9%; P = 0.003) and higher modified FPE (mTICI ≥ 2b after a single pass) rate (65.9% vs 46.8%; P = 0.001). The use of extra-LB-DAC was an independent factor in predicting FPE (odds ratio 1.982, 95% confidence interval 1.250-3.143, P = 0.004).

CONCLUSION

Our results suggest that in combined LB-DAC/stent-retriever thrombectomy, a larger aspiration catheter inner diameter is associated with higher rates of FPE and mFPE.

A review of mechanical thrombectomy techniques for acute ischemic stroke

Mechanical thrombectomy is established as standard of care in the management of acute ischemic stroke due to large vessel occlusion and evidence-based guidelines for mechanical thrombectomy have been defined. As research continues to further expand the eligibility criteria for thrombectomy and the number of thrombectomy procedures increase worldwide, there is also growing focus on innovation of thrombectomy devices, procedural techniques, and related outcomes. Thrombectomy primarily involves use of stent retrievers and distal aspiration techniques, but variations and different combinations of techniques have been reported. As this is a rapidly evolving area in stroke management, there is debate as to which, if any, of these techniques leads to improved clinical outcomes over another and there is a lack of data comparing them. In this review, currently published and distinct techniques of mechanical thrombectomy are described methodically along with illustrations to aid in understanding the subtle differences between the techniques. The perceived benefits of each variation are discussed.

Different types of percutaneous endovascular interventions for acute ischemic stroke

BACKGROUND

Acute ischemic stroke (AIS) is the abrupt reduction of blood flow to a certain area of the brain which causes neurologic dysfunction. Different types of percutaneous arterial endovascular interventions have been developed, but as yet there is no consensus on the optimal therapy for people with AIS.

OBJECTIVES

To compare the safety and efficacy of different types of percutaneous arterial endovascular interventions for treating people with AIS.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 4 of 12, 2022), MEDLINE Ovid (1946 to 13 May 2022), Embase (1947 to 15 May 2022), Science Citation Index Web of Science (1900 to 15 May 2022), Scopus (1960 to 15 May 2022), and China Biological Medicine Database (CBM; 1978 to 16 May 2022). We also searched the ClinicalTrials.gov trials register and the World Health Organization (WHO) International Clinical Trials Registry Platform to 16 May 2022.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing one percutaneous arterial endovascular intervention with another in treating adult patients who have a clinical diagnosis of AIS due to large vessel occlusion and confirmed by imaging evidence, including thrombo-aspiration, stent-retrieval thrombectomy, aspiration-retriever combined technique, and thrombus mechanical fragmentation.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the literature searches, identified eligible trials, and extracted data. A third review author participated in discussions to reach consensus decisions when any disputes occurred. We assessed risk of bias and applied the GRADE approach to evaluate the quality of the evidence. The primary outcome was rate of modified Rankin Scale (mRS) of 0 to 2 at three months. Secondary outcomes included the rate of modified Thrombolysis In Cerebral Infarction (mTICI) of 2b to 3 postprocedure, all-cause mortality within three months, rate of intracranial hemorrhage on imaging at 24 hours, rate of symptomatic intracranial hemorrhage at 24 hours, and rate of procedure-related adverse events within three months.

MAIN RESULTS

Four RCTs were eligible. The current meta-analysis included two trials with 651 participants comparing thrombo-aspiration with stent-retrieval thrombectomy. We judged the quality of evidence to be high in both trials according to Cochrane's risk of bias tool RoB 2. There were no significant differences between thrombo-aspiration and stent-retrieval thrombectomy in rate of mRS of 0 to 2 at three months (risk ratio [RR] 0.97, 95% confidence interval [CI] 0.82 to 1.13; P = 0.68; 633 participants; 2 RCTs); rate of mTICI of 2b to 3 postprocedure (RR 1.01, 95% CI 0.95 to 1.07; P = 0.77; 650 participants; 2 RCTs); all-cause mortality within three months (RR 1.01, 95% CI 0.74 to 1.37; P = 0.95; 633 participants; 2 RCTs); rate of intracranial hemorrhage on imaging at 24 hours (RR 1.03, 95% CI 0.86 to 1.24; P = 0.73; 645 participants; 2 RCTs); rate of symptomatic intracranial hemorrhage at 24 hours (RR 0.90, 95% CI 0.49 to 1.68; P = 0.75; 645 participants; 2 RCTs); and rate of procedure-related adverse events within three months (RR 0.98, 95% CI 0.68 to 1.41; P = 0.90; 651 participants; 2 RCTs). Another two included studies reported no differences for the comparisons of combined therapy versus stent-retrieval thrombectomy or thrombo-aspiration. One RCT is ongoing.

AUTHORS' CONCLUSIONS

This review did not establish any difference in safety and effectiveness between the thrombo-aspiration approach and stent-retrieval thrombectomy for treating people with AIS. Furthermore, the combined group did not show any obvious advantage over either intervention applied alone.

AXS Vecta 0.071-0.074 Inch Aspiration Catheters for Mechanical Thrombectomy: Case Series and Literature Review

Aspiration catheters are widely used for thrombectomy either alone or in combination with a stent-retriever, with a distal inner diameter and trackability keys to their success. In an illustrative case series, we report our clinical experience with AXS Vecta (Stryker Neurovascular, Fremont, CA, USA), available in both 0.071-inch and 0.074-inch distal inner diameters, including the first 2 Vecta 74 cases reported. A literature review on AXS Vecta is also provided. In our series, 9 thrombectomies were performed (Vecta 71: 2 M1, 5 M2 occlusions; Vecta 74: 1 M1 and 1 ICA-terminus occlusion). The AXS Vecta was successfully delivered to the target site in all cases. In 7 of 9 cases, the catheter was delivered over a Tenzing 7 delivery catheter (Route 92 Medical, San Mateo, CA, USA). For 2 of 9 combination approach cases, Vecta was delivered using the stent-retriever wire as a rail. The median improvement in NIHSS score during hospitalization was 9 (IQR 5-12). Successful mTICI 2C or 3 recanalization was achieved in 8 of 9 (89%) patients after a median 2 (IQR 1-2) passes. Our median groin-to-reperfusion time was 23 (IQR 12.5-32) minutes, with no procedural complications. Two previous clinical studies of a total of 29 patients treated with Vecta 71 reported successful mTICI 2b-3 recanalization in 89-90% of cases. The Median groin-to-reperfusion time was 30 minutes. Complications were seen in 2 of 29 (6.9%) cases (vessel perforation and/or intracerebral hemorrhage). These data support the efficacy, deliverability, and safety of AXS Vecta for mechanical thrombectomy.

Combined balloon guide catheter, aspiration catheter, and stent retriever technique versus balloon guide catheter and stent retriever alone technique: a systematic review and meta-analysis

BACKGROUND

The use of a combination of balloon guide catheter (BGC), aspiration catheter, and stent retriever in acute ischemic stroke thrombectomy has not been shown to be better than a stent retriever and BGC alone, but this may be due to a lack of power in these studies. We therefore performed a meta-analysis on this subject.

METHODS

A systematic literature search was performed on PubMed, Scopus, Embase/Ovid, and the Cochrane Library from inception to October 20, 2021. Our primary outcomes were the rate of successful final reperfusion (Treatment in Cerebral Ischemia (TICI) 2c-3) and first pass effect (FPE, defined as TICI 2c-3 in a single pass). Secondary outcomes were 3 month functional independence (modified Rankin Scale score of 0-2), mortality, procedural complications, embolic complications, and symptomatic intracranial hemorrhage (SICH). A meta-analysis was performed using RevMan 5,4, and heterogeneity was assessed using the I² test.

RESULTS

Of 1629 studies identified, five articles with 2091 patients were included. For the primary outcomes, FPE (44.9% vs 45.4%, OR 1.04 (95% CI 0.90 to 1.22), I²=57%) or final successful reperfusion (64.5% vs 68.6%, OR 0.98 (95% CI 0.81% to 1.20%), I²=85%) was similar between the combination technique and stent retriever only groups. However, the combination technique had significantly less rescue treatment (18.8% vs 26.9%; OR 0.70 (95% CI 0.54 to 0.91), I²=0%). This did not translate into significant differences in secondary outcomes in functional outcomes, mortality, emboli, complications, or SICH.

CONCLUSION

There was no significant difference in successful reperfusion and FPE between the combined techniques and the stent retriever and BGC alone groups. Neither was there any difference in functional outcomes, complications, or mortality.

Stent Retriever or Aspiration Catheter Alone vs Their Combination as the First-Line Thrombectomy in Acute Stroke

BACKGROUND

The single-device simplicity for mechanical thrombectomy (MT) is now challenged by the complementary efficacy of dual-device first-line with a stent retriever and an aspiration catheter.

OBJECTIVE

To compare the outcomes after MT initiated with a single device vs dual devices in acute anterior circulation large vessel occlusion.

METHODS

Patients who underwent MT for acute internal carotid artery (ICA) or M1 occlusion between 2015 and 2020 were retrospectively analyzed. We divided patients into 2 groups: single-device first-line, defined as patients who underwent first-device pass with either a stent retriever or aspiration catheter, and dual-device first-line, defined as first-device pass with both devices.

RESULTS

One hundred forty-one patients were in the single-device group, and 119 were in the dual-device group. In the dual-device group, coiling or kinking of the extracranial ICA was more frequent ( P = .07) and the guide catheters were less frequently navigated to the ICA ( P < .001). 37% of the single-device group was converted to dual-device use. The proportions of mTICI ≥ 2c after the first pass were similar (33% vs 32%. adjusted odds ratio 0.91, 95% CI 0.51-1.62). An mRS score of 0 to 2 at 3 months was achieved similarly (53% vs 48%, P = .46). The total cost for thrombectomy devices was lower in the single-device group ( P < .001).

CONCLUSION

The proportions of first-pass mTICI ≥ 2c were not different between the 2 groups with similar functional outcomes, although the dual-device group more likely to have unfavorable vascular conditions.

Is aspiration an effective acute stroke treatment in older adults?

Introduction

Clinical outcomes after interventional stroke treatment rely on several factors, with older age being associated with poorer results, which are mainly attributed to patient's comorbidities and medications. The delivery of an aspiration catheter could be hindered by carotid tortuosity, which is more prevalent in elderly patients with increasing age. In this study, we aimed to compare the clinical and angiographic outcomes of a direct aspiration first-pass technique in interventional stroke treatment for elderly patients compared with younger patients.

Materials and methods

A total of 162 patients (92 women and 70 men, aged between 35 and 94 years +/- 12.4 years) were included in this study. Patients who were treated in a comprehensive stroke center due to a large-vessel occlusion stroke using aspiration as the first-choice treatment were included in this study. To evaluate carotid arteries, the tortuosity index (TI) was calculated for each segment of each carotid pathway.

Results

Age correlated significantly with the presence of carotid tortuosity (R = 0.408, p = 0.000), extracranial length ratio (R = 0.487, p = 0.000), and overall length ratio (R = 0.467, p = 0.000). No significant associations were found with coiling, kinking, or intracranial length ratio. Successful aspiration-based recanalization rate decreased with increasing age, and the differences between the age subgroups were not statistically significant. A comparison of the extreme subgroups, i.e., <60 years old vs. ≥80 years old, did not yield a statistically significant change (p = 0.068).

Conclusion

Successful aspiration-based recanalization rate decreased with increasing age; however, these differences were not significant. Clinical outcomes did not significantly differ with regard to carotid tortuosity, regardless of the time of assessment. Neither intracranial nor extracranial tortuosity was significantly associated with reperfusion-related complications in either of the age subgroups.

Frontline thrombectomy strategy and outcome in acute basilar artery occlusion

BACKGROUND

Novel thrombectomy strategies emanate expeditiously day-by-day counting on access system, clot retriever device, proximity to and integration with the thrombus, and microcatheter disengagement. Nonetheless, the relationship between native thrombectomy strategies and revascularization success remains to be evaluated in basilar artery occlusion (BAO).

PURPOSE

To compare the safety and efficacy profile of key frontline thrombectomy strategies in BAO.

METHODS

Retrospective analyses of prospectively maintained stroke registries at two comprehensive stroke centers were performed between January 2015 and December 2019. Patients with BAO selected after MR imaging were categorized into three groups based on the frontline thrombectomy strategy (contact aspiration (CA), stent retriever (SR), or combined (SR+CA)). Patients who experienced failure of clot retrieval followed by an interchanging strategy were categorized as a fourth (switch) group. Clinicoradiological features and procedural variables were compared. The primary outcome measure was the rate of complete revascularization (modified Thrombolysis in Cerebral Infarction (mTICI) grade 2c-3). Favorable outcome was defined as a 90 day modified Rankin Scale score of 0-2.

RESULTS

Of 1823 patients, we included 128 (33 underwent CA, 35 SR, 35 SR +CA, and 25 switch techniques). Complete revascularization was achieved in 83/140 (59%) primarily analyzed patients. SR +CA was associated with higher odds of complete revascularization (adjusted OR 3.04, 95% CI 1.077 to 8.593, p=0.04) which was an independent predictor of favorable outcome (adjusted OR 2.73. 95% CI 1.152 to 6.458, p=0.02). No significant differences were observed for symptomatic intracranial hemorrhage, functional outcome, or mortality rate.

CONCLUSION

Among BAO patients, the combined technique effectively contributed to complete revascularization that showed a 90 day favorable outcome with an equivalent complication rate after thrombectomy.

Comparison of mechanical thrombectomy techniques in an in vitro stroke model: How to obtain a first pass recanalization?

BACKGROUND

Since mechanical thrombectomy (MT) has proven to be effective in the treatment of acute ischemic stroke (AIS), significant research has been dedicated to establishing procedural techniques offering best rate of first pass effect (FPE). In this study, we compared the efficacy of different techniques in vitro to achieve the first pass recanalisation (FPR).

METHODS

In vitro MT procedures were performed using a realistic silicone model of the human cerebral vasculature. The MT with stent retriever (SR) were performed with manual co-aspiration through the respective access catheter and intermediate catheter (IC), with Solumbra or partial retrieval techniques into the IC. Two SRs (Solitaire and EmboTrap) were selected to retrieve both red blood cells (RBC) rich and fibrin-rich clots. FPR rates were recorded for each case.

RESULTS

Overall, 144 MT were performed. FPR rates using the partial retrieval and Solumbra technique were of 100% and 87%, respectively (p = 0.01). The rate of FPR was of 92% using the balloon-guide catheter (BGC) compared to 64% with the guide catheter (GC) (p = 0.0001). With an IC, no differences were found between using a BGC or a GC (87.9% vs 89,6%, p = 0.75). No significant difference was observed between the Embotrap and the Solitaire device for the rate of FPR (82% and 74%, respectively; p = 0.23).

CONCLUSIONS

In this study, FPR rates were higher with the use of an IC associated with the partial retrieval technique, regardless the guide catheter, the SR, or the clot composition. The less effective technique was the association of GC and SR, without an IC.

Mothership vs. drip-and-ship: evaluation of initial treatment strategies for acute ischemic stroke in a well-developed network of specialized hospitals

PURPOSE

Two strategies of initial patient care exist in endovascular thrombectomy (ET) depending on the site of initial admission: the mothership (MS) and drip-and-ship (DnS) principles. This study compares both strategies in regard to patient outcome in a local network of specialized hospitals.

METHODS

Two-hundred-and-two patients undergoing ET in anterior circulation ischemic stroke between June 2016 and May 2018 were enrolled. Ninety two patients were directly admitted to our local facility (MS), One-hundred-and-ten were secondarily referred to our facility. Group comparisons between admission strategies in three-months modified Rankin Scale (mRS), Maas Score and Alberta-Stroke-Program-Early-computed-tomography-score (ASPECTS), National-Institutes-of-Health-Stroke-Scale (NIHSS), age and onset-to-recanalization-time were performed. Correlation between admission strategy and mRS was calculated. A binary logistic regression model was computed including mRS as dependent variable.

RESULTS

There were neither significant group differences in three-months mRS between MS and DnS nor significant correlations. Patients tended to achieve a better outcome with DnS. Collateralization status differed between MS and DnS (p = 0.003) with better collateralization in DnS. There were no significant group differences in NIHSS or ASPECTS but in onset-to-recanalization-time (p < 0.001) between MS and DnS. Binary logistic regression showed a high explanation of variance of mRS but no significant results for admission strategy.

CONCLUSIONS

Functional outcome in patients treated with ET is comparable between the MS and DnS principles. Tendentially better outcome in the DnS subgroup may be explained by selection bias due to a higher willingness to apply ET in patients with worse baseline conditions (e.g. worse collateralization), if patients undergoing MS are already on site.

Mechanical thrombectomy in stroke patients with acute occlusion of the M1- compared to the M2-segment: Safety, efficacy, and clinical outcome

PURPOSE

Endovascular treatment (ET) in occlusions of the M1- and proximal M2-segment of the middle cerebral artery (MCA) is an established procedure. In contrast, ET in distal M2-occlusions has not been sufficiently evaluated yet. The purpose of this study was to assess relevant parameters for clinical outcome, efficacy, and safety of patients undergoing ET in M1-, proximal M2-, and distal M2-occlusions.

METHODS

One hundred seventy-four patients undergoing ET in acute ischemic stroke with an occlusion of the M1- or M2-segment of the MCA were enrolled prospectively. Non-parametric analysis of variance in 3-month mRS, TICI scale, and complication rates were performed with Kruskal-Wallis test between M1- and proximal and distal M2-occlusions. Subsequent pairwise group comparisons were calculated using Mann-Whitney U-tests. Binary logistic regression models were calculated for each occlusion site.

RESULTS

There were no significant group differences in 3-month mRS, mTICI scale, or complication rates between M1- and M2-occlusions nor between proximal and distal M2-occlusions. Binary logistic regression in patients with M1-occlusions showed a substantial explanation of variance (NR2=0.35). NIHSS (p=0.009) and Maas Score as parameter for collateralization (p=0.01) appeared as significant contributing parameters. Binary logistic regression in M2-occlusions showed a high explanation of variance (NR2=0.50) of mRS but no significant factors.

CONCLUSIONS

Clinical outcome and procedural safety of patients with M2-occlusions undergoing ET are comparable to those of patients with M1-occlusions. Clinical outcome of patients with M1-occlusions undergoing ET is primarily influenced by the initial neurological deficit and the collateralization of the occlusions. By contrast, clinical outcome in patients with M2-occlusions undergoing ET is more multifactorial.

Efficacy of Balloon Guide Catheter-Assisted Thrombus Repair in Stroke Treatment: A Retrospective Survey in China

Background

The first-pass (FP) effect, defined by successful cerebral reperfusion from a single pass of an endovascular stentriever, was associated with shorter procedural times and possible improved outcomes in patients with ischemic stroke secondary to large vessel occlusion. The adjunctive use of balloon guide catheter (BGC) may increase the rates of the first-pass effect. In this retrospective study we examined the impact of BGC on the first-pass effect in acute stroke patients.

Methods

We included patients with acute ischemic stroke with large vessel occlusion treated by endovascular thrombectomy from 2018 to 2019. We categorized the cases into BGC and non-BGC groups. Differences in time metrics and outcomes were compared.

Result

One hundred and thirty-two patients were included, and sixty-two were in BGC group (47.0%). The median procedural time was shorter (83.0 minutes vs 120.0 minutes, P = 0.000), and FP rate was higher in BGC group (58.1% vs 32.9%, P = 0.004) compared with non-BGC group. Proportion of modified Thrombolysis in Cerebral Infarction (mMTICI) 3 was higher (66.1% vs 37.1%, P = 0.001), and modified Rankin Scale (mRS) 0 to 2 was higher (59.7% vs 41.4%, P = 0.036) in BGC group compared with non-BGC group. In addition, BGC was associated with successful reperfusion odds ratio, 0.383; 95% confidence interval: 0.174-0.847; P = 0.018). The FP rate of BGC in the distal ICA was higher than that in the proximal ICA (87.5% vs 39.5%, P = 0.000), and the good clinical outcome rate at 90 days in the distal ICA was also higher than that in the proximal ICA (91.7% vs 39.5%, P = 0.000).

Conclusion

We showed that BGC shortened the procedural time and increased the rate of the successful FP. We recommend that BGC could be considered the preferred technique for endovascular intervention in stroke.

Combined stent-retriever and aspiration intra-arterial thrombectomy performance for fragmentable blood clots: A proof-of-concept computational study

Mechanical thrombectomy (MT) treatment of acute ischemic stroke (AIS) patients typically involves use of stent retrievers or aspiration catheters alone or in combination. For in silico trials of AIS patients, it is crucial to incorporate the possibility of thrombus fragmentation during the intervention. This study focuses on two aspects of the thrombectomy simulation: i) Thrombus fragmentation on the basis of a failure model calibrated with experimental tests on clot analogs; ii) the combined stent-retriever and aspiration catheter MT procedure is modeled by adding both the proximal balloon guide catheter and the distal access catheter. The adopted failure criterion is based on maximum principal stress threshold value. If elements of the thrombus exceed this criterion during the retrieval simulation, then they are deleted from the calculation. Comparison with in-vitro tests indicates that the simulation correctly reproduces the procedures predicting thrombus fragmentation in the case of red blood cells rich thrombi, whereas non-fragmentation is predicted for fibrin-rich thrombi. Modeling of balloon guide catheter prevents clot fragments' embolization to further distal territories during MT procedure.

Novel synthetic clot analogs for in-vitro stroke modelling

Purpose

The increased demand for training of mechanical thrombectomy in ischemic stroke and development of new recanalization devices urges the creation of new simulation models both for training and device assessment. Clots properties have shown to play a role in procedural planning and thrombectomy device effectiveness. In this study, we analyzed the characteristics and applicability of completely synthetic, animal-free clots in the setting of an in-vitro model of mechanical thrombectomy for training and device assessment.

Methods

Synthetic clots based on agarose (n = 12) and silicone (n = 11) were evaluated in an in-vitro neurointervention simulation of mechanical thrombectomy with clot extraction devices. Calcified clots of mixed nature were simulated with addition of 3D printed structures. 9 clots were excluded due to insufficient vessel occlusion and failure to integrate with clot extraction device. Synthetic thrombi were characterized and compared using a categorical score-system on vessel occlusion, elasticity, fragmentation, adherence and device integration.

Results

Both agarose-based and silicone-based clots demonstrated relevant flow arrest and a good integration with the clot extraction device. Silicone-based clots scored higher on adherence to the vessel wall and elasticity.

Conclusion

Selected synthetic clots can successfully be implemented in an in-vitro training environment of mechanical thrombectomy. The clots’ different properties might serve to mimic fibrin-rich and red blood cell-rich human thrombi.

Comparing the Conventional and Balloon-Guided Catheter-Assisted SWIM Technology for the Treatment of Acute Ischemic Stroke

Objective

Acute ischemic stroke is common in elder patients. This study investigates whether using the balloon-guided catheter (BGC) would improve the effect of stent thrombectomy (Solitaire FR With Intracranial Support Catheter for Mechanical Thrombectomy, SWIM) for patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO).

Method

The data of 209 patients with AIS-LVO underwent SWIM were collected retrospectively from January 2017 to June 2021. These patients were divided into two groups based on whether they used of BGC or not. The propensity score matching (PSM) analysis was used to compare the differences in the first pass effect (FPE), successful recanalization, embolus escape rate, symptomatic intracranial hemorrhage (sICH), 90-day clinical favorable outcome, 90-day all-cause mortality, and complications in the patients treated with SWIM combined with balloon-guided catheter or conventional catheter.

Results

Among the 209 patients, 44 patients were treated with BGC and 165 patients were not. After matching, a total of 111 patients were included. The results showed that there was no statistical difference in FPE (35.1% in non-BGC group compared to 24.3% in BGC group, matched RR, 0.59; 95% CI, 0.24–1.44), successful recanalization (89.2 vs. 91.9%, matched RR, 1.37; 95%CI, 0.34–5.51), embolus escape (6.8 vs. 8.1%, matched RR, 1.22; 95%CI, 0.28–5.40), sICH (8.1 vs. 13.5%; matched RR, 1.77; 95%CI 0.50–6.24), 90-day clinical favorable outcome (48.7 vs. 54.1%, matched RR, 1.11; 95%CI 0.51–2.46), 90-day all-cause mortality (17.6 vs. 21.6%, matched RR, 1.29; 95%CI 0.48–3.47), and the incidence of complications (6.8 vs. 5.4%, matched RR, 0.79 95%CI 0.15–4.27). These results indicate that using SWIM as the first-line treatment for patients with AIS-LVO, there is no statistical significance in FPE, final successful recanalization, distal emboli, sICH, procedural time, 90-day favorable outcome, 90-day mortality, and complications with or without BGC.

Conclusion

Balloon-guided catheter does not affect the result of using SWIM as the first-line treatment for patients with AIS-LVO. Our results will guide daily practice, with the adoption of the use of a guided catheter without a balloon.

A prospective, first-in-human use of the NeVa mechanical thrombectomy device for patients with acute coronary syndromes

BACKGROUND

There is no established technique for managing large thrombus burden (LTB) in patients with acute coronary syndrome (ACS).

AIMS

The aim of this study was to assess the safety and efficacy of the NeVa (Vesalio) mechanical thrombectomy device (MTD) in ACS patients with LTB.

METHODS

Consecutive patients with ACS and LTB were treated with the NeVa MTD as the primary vessel recanalisation and thrombus removal modality, followed by conventional intervention. We further developed a bench model and applied to a subset of patients, a vacuum-assisted aspiration technique, exploiting 6 Fr-compatible conventional guiding catheter extensions, as an adjudicative manoeuvre to the use of stent-based MTD. A core laboratory reviewed the angiographic images for procedural complications, Thrombolysis In Myocardial Infarction (TIMI) flow, myocardial blush grade (MBG) and TIMI thrombus grade (TTG).

RESULTS

Between November 2019 and March 2021, 61 patients underwent thrombectomy with the NeVa device. Non-flow limiting and reversible coronary spasm occurred in 14 (23%) patients. One patient (#10) suffered from side branch embolisation, which was successfully treated with the NeVa, triggering the development of a vacuum-assisted aspiration technique in a bench model, which was then applied to the subsequent 51 patients. No other device-related complications occurred. After NeVa use, TIMI flow <3 decreased from 68.3% at baseline to 10.3% (p<0.001), MBG <2 from 65% to 27.6% (p<0.001), TTG ≥3 from 96.7% to 43.2% (p<0.001), respectively.

CONCLUSIONS

In patients with LTB, the NeVa MTD was safe and associated with high rates of vessel recanalisation and thrombus removal. The concomitant use of vacuum-assisted aspiration has potential to improve the effectiveness and safety of the technique.

Acute embolic stroke with large-vessel occlusion: does contact aspiration thrombectomy show superiority?

AIM

To compare the efficacy between contact aspiration thrombectomy and stent retriever thrombectomy in the treatment of acute embolic stroke patients with large vessel occlusion.

MATERIALS AND METHODS

Between January 2019 and June 2020, data from consecutive acute ischaemic stroke patients who underwent either endovascular contact aspiration or stent retriever thrombectomy were analysed at one institution. The primary outcome was the full 90-day modified Rankin Scale (mRS) score. Ordinal logistic regression analysis was used to assess the association between thrombectomy approach and functional outcomes.

RESULTS

A total of 156 patients were analysed. Among them, 57 (36.5%) patients underwent primary aspiration thrombectomy, while 99 (63.5%) patients underwent primary stent retriever thrombectomy. The median procedure time was significantly shorter in patients treated with aspiration (37 versus 56 minutes; p<0.001). Compared with those of patients who underwent stent retriever thrombectomy, successful recanalisation rates and favourable functional outcome rates were higher in patients who underwent the aspiration approach (94.7% versus 77.8%, p=0.006; 49.1% versus 27.3%, p=0.006, respectively). Ordinal logistic regression analysis showed that aspiration thrombectomy was independently associated with a good functional outcome (adjusted common odds ratio, 0.30, 95% confidence interval: 0.16-0.60, p<0.001).

CONCLUSION

Among the specific patients with large vessel occlusion in acute embolic stroke, the use of aspiration thrombectomy compared with stent retriever thrombectomy resulted in a greater likelihood of favourable neurological outcomes; however, because of study limitations, these findings should be interpreted as preliminary and require further study to confirm these results.

Effectiveness of Anchoring with Balloon Guide Catheter and Stent Retriever in Difficult Mechanical Thrombectomy for Large Vessel Occlusion

Objective

A distal navigation of a large bore aspiration catheter during mechanical thrombectomy (MT) is important. However, delivering a large bore aspiration catheter is difficult to a tortuous or atherosclerotic artery. We report the experience of anchoring with balloon guide catheter (BGC) and stent retriever to facilitate the passage of an aspiration catheter in MT.

Methods

When navigating an aspiration catheter failed with a conventional co-axial microcatheter delivery, an anchoring technique was used. Two types of anchoring technique were applied to facilitate distal navigation of a large bore aspiration catheter during MT. First, a passage of aspiration catheter was attempted with a proximal BGC anchoring technique. If this technique also failed, another anchoring technique with distal stent retriever was tried. Consecutive patients who underwent MT with an anchoring technique were identified. Details of procedure, radiologic outcomes, and safety variables were evaluated.

Results

A total of 67 patients underwent MT with an anchoring technique. Initial trial of aspiration catheter passage with proximal BGC anchoring technique was successful for 35 patients (52.2%) and the second trial with distal stent retriever anchoring was successful for 32 patients (47.8%). Overall, navigation of a large bore aspiration catheter was successful for all patients (100%) without any procedure related complications.

Conclusion

Our study showed the usefulness of anchoring technique with proximal BGC and distal stent retriever during MT, especially in those with an unfavorable anatomical structure. This technique could be an alternative option for delivering an of aspiration catheter to a distal location.

Patient and procedure selection for mechanical thrombectomy: Toward personalized medicine and the role of artificial intelligence

Mechanical thrombectomy (MT) for ischemic stroke due to large vessel occlusion is standard of care. Evidence-based guidelines on eligibility for MT have been outlined and evidence to extend the treatment benefit to more patients, particularly those at the extreme ends of a stroke clinical severity spectrum, is currently awaited. As patient selection continues to be explored, there is growing focus on procedure selection including the tools and techniques of thrombectomy and associated outcomes. Artificial intelligence (AI) has been instrumental in the area of patient selection for MT with a role in diagnosis and delivery of acute stroke care. Machine learning algorithms have been developed to detect cerebral ischemia and early infarct core, presence of large vessel occlusion, and perfusion deficit in acute ischemic stroke. Several available deep learning AI applications provide ready visualization and interpretation of cervical and cerebral arteries. Further enhancement of AI techniques to potentially include automated vessel probe tools in suspected large vessel occlusions is proposed. Value of AI may be extended to assist in procedure selection including both the tools and technique of thrombectomy. Delivering personalized medicine is the wave of the future and tailoring the MT treatment to a stroke patient is in line with this trend.

Simplified classification of cavernous internal carotid artery tortuosity: a predictor of procedural complexity and clinical outcomes in mechanical thrombectomy

OBJECTIVES

Thromboaspiration catheters are increasingly used for the endovascular treatment of large vessel stroke (LVS), while tortuous vascular anatomy still remains one major challenge in mechanical thrombectomy. Prompt assessing and understanding cavernous internal carotid artery (cICA) tortuosity may help to predict procedural complexities of mechanical thrombectomy and thus improve the clinical outcomes.

METHODS

A retrospective review was performed on a cohort of LVS patients with thromboaspiration catheter. Simplified classification of cICA tortuosity was applied by measurement of the angle of the posterior genus (P) and the height from the peak of the posterior genu to the trough of the anterior genu (D). Statistical analyses were performed to analyze differences among the obtained types of cICA tortuosity regarding procedural characteristics and clinical outcomes.

RESULTS

A total of 150 patients with LVS proximal to the internal ICA terminus and middle cerebral artery (MCA) were included in this study, and three types of cICA tortuosity were defined by the simplified classification. The index, such as patients ages and hypertension, procedural fluoroscopy time, the degree of cICA tortuosity, first-pass success, final reperfusion, and 90-day mortality showed significant differences among the three types (P < 0.05), while 90-day good outcome (mRS 0-2) only presented significant difference between Type I and Type III (P < 0.05).

CONCLUSIONS

The study indicated that the grading of cICA tortuosity is highly correlated with procedural complexity and clinical outcome in mechanical thrombectomy. The proposed classification system may be helpful in pre-procedure prognostication complexity and clinical outcomes.Abbreviations:LVS: large vessel stroke; cICA: cavernous internal carotid artery; mRS: modified Rankin Scale; AIS: acute ischemic stroke; MCA: middle cerebral artery; M1: first division of middle cerebral artery; M2: second division of middle cerebral artery; M3: third division of middle cerebral artery; TICI: Thrombolysis In Cerebral Infarction; TICI 2b: two-thirds of occluded territory reperfusion; DSA: digital subtraction angiography; FT: fluoroscopy time.

A fully radiopaque hybrid stent retriever versus a precursor device: Outcome, efficacy, and safety in large vessel stroke

BACKGROUND AND PURPOSE

The aim of this multicenter study was to compare the clinical outcome, safety, and efficacy of the full-length radiopaque Aperio Hybrid stent retriever (APH) with the precursor Aperio thrombectomy device (AP).

METHODS

Multicentric retrospective analysis of patients with stroke, treated with the APH and AP due to an acute ischemic stroke by large vessel occlusions in the anterior or posterior circulation, was performed. We focused on the comparison of favorable clinical outcome (modified Rankin Scale, 0-2) after 3 months, favorable reperfusion rates (thrombolysis in cerebral infarction scale ≥ 2b), and the complication rate.

RESULTS

A total of 51 patients (female: n = 33, 64.7%, mean age 73 ± 16 years) with a median baseline National Institutes of Health Stroke Scale: 15 were treated with the APH or AP. Favorable outcome in patients treated with APH was excellent (44.0%) and comparable to the AP (36.8%). The rate of final favorable reperfusion for both devices was outstanding (APH 31/31 and AP 20/20). The overall complication rate for the APH was slightly higher compared to the AP (32.3%/15.0%). Symptomatic intracranial hemorrhage was recorded in 0 of 51 cases. The all-cause mortality rate at 90 days was 20.0% for the APH and comparable for the AP (21.1%).

CONCLUSIONS

Comparable clinical outcome, efficacy, and safety of the AP and the recently introduced APH were demonstrated. Both devices appeared feasible, efficient, and safe with regard to endovascular treatment in large vessel occlusion.

Repeated-Manual Aspiration with Maximum Pressure (r-MAX): A New Technique of Mechanical Thrombectomy Using Syringe Aspiration

Objective

We report a new contact aspiration technique using syringe aspiration called repeated-manual aspiration with maximum pressure (r-MAX).

Case Presentation

From January 2020 to May 2021, 18 patients underwent mechanical thrombectomy with r-MAX for occlusion of the internal carotid artery, the first division of the middle cerebral artery (M1), and basilar artery occlusion. In this method, the aspiration catheter is first guided to the occlusion site, and then, two VacLok syringes are connected to the aspiration catheter. Next, the three-way stopcock is released in one direction. After 15 seconds, the direction of the three-way stopcock is switched. In the meantime, negative pressure is reapplied through the syringe, and the direction of the three-way stopcock is switched again. After reapplying negative pressure through the syringe and switching the three-way stopcock two more times, the aspiration catheter is removed. First-pass thrombolysis in cerebral infarction (TICI) scale 3 recanalization was achieved in 11 out of 18 patients (61.1%). In all, 11 patients (61.1%) achieved modified Rankin Scale scores of 0-2 at 90 days. Asymptomatic hemorrhage was observed in two patients (11.1%), and no patients had symptomatic hemorrhage.

Conclusion

The r-MAX technique using syringe aspiration can be employed as one of the methods of contact aspiration.

Thrombectomy for acute large vessel occlusion in posterior and anterior circulation: a single institutional retrospective observational study

PURPOSE

Thrombectomy has been the gold standard therapy for anterior circulation occlusion; however, studies regarding thrombectomy in posterior circulation are lacking. In this study, we compared the efficiency of thrombectomy for acute large vessel occlusion between the posterior and anterior circulation at a single institution.

METHODS

We retrospectively analyzed consecutive patients who underwent thrombectomy for acute large vessel occlusion at our institution between August 2014 and April 2021. Differences in the clinical background, time course, and treatment technique and outcomes were evaluated between anterior and posterior circulation occlusions.

RESULTS

Overall, 353 patients (225 men and 128 women) were included: 314 patients had anterior circulation occlusion and 39 patients had posterior circulation occlusion. Between the patients with anterior and posterior circulation occlusions, the National Institutes of Health Stroke Scale (NIHSS) score (16 [12-21] vs. 29 [19-34], respectively, p < 0.001), door-to-puncture time (65 [45-99] vs. 99 [51-121] min, respectively, p = 0.018), and mortality (22 [7%] vs. 8 [20.5%] patients, respectively, p = 0.010) were significantly different; however, favorable outcome was not significantly different.

CONCLUSION

Higher NIHSS score, delayed treatment, and higher mortality were observed in posterior circulation occlusion than in anterior circulation occlusion; successful reperfusion and favorable outcomes were similar between them. Similar favorable outcomes and reperfusion ratio to the anterior circulation might be achieved also in the posterior circulation; however, delayed treatment and the optimal first-pass strategy might need further improvement.

The claw sign predicts first-pass effect in mechanical thrombectomy for cerebral large vessel occlusion in the anterior circulation

Background:

Mechanical thrombectomy (MT) is an effective treatment for acute cerebral large vessel occlusion (LVO). Complete recanalization of vessels in a single procedure is defined as the first-pass effect (FPE) and is associated with good prognosis. In this study, angiographic clot protruding sign termed the “claw sign,” was examined as candidate preoperative imaging factor for predicting the FPE.

Methods:

We retrospectively analyzed data from 91 consecutive patients treated for acute LVO in the anterior circulation by MT between January 2014 and December 2019. The claw sign was defined as a thrombus that protruded proximally by more than half of the diameter of the parent artery. Radiological findings such as claw sign, clinical and etiological features, and outcomes were compared between groups with and without successful FPE. Multivariate analysis was conducted to evaluate perioperative factors associated with FPE.

Results:

FPE was achieved in 26 of 91 (28.6%) patients and the claw sign was observed in 34 of 91 (37.4%) patients. The claw sign was significantly more frequent in the successful FPE group than in the failed FPE group (53.8% vs. 30.8%; P = 0.040). After the multivariate analysis, the claw sign was the only pretreatment parameter that could predict FPE (odds ratio, 2.67; 95% confidence interval, 1.01–7.06; P = 0.047).

Conclusion:

The claw sign is an angiographic imaging factor that might predict FPE after MT for anterior circulation acute ischemic stroke.

Clinical protocol of the ischemic stroke patients treatment

Today in Ukraine there is no single standardized protocol for the treatment of patients in the acute period of ischemic stroke using modern methods of diagnosis and treatment, which include thrombolytic therapy and endovascular treatment. This protocol was created and implemented in Scientific-practical Center of endovascular neuroradiology, NAMS of Ukraine and is based on the latest recommendations of AHA/ASA and ESO, as well as registers of patients with ischemic stroke. The main purpose of this publication is the creation and implementation of «instructions» for the diagnosis and selection of objective tactics for treating patients in the acute period of ischemic stroke.

High D-dimer concentration is a significant independent prognostic factor in patients with acute large vessel occlusion undergoing endovascular thrombectomy

OBJECTIVE

This study aimed to investigate prognostic factors that affect modified Rankin Scale (mRS) score at 3 months after onset in acute stroke patients with large vessel occlusion (LVO) undergoing endovascular thrombectomy.

METHODS

We retrospectively examined 87 consecutive patients who underwent endovascular cerebral thrombectomy for acute anterior circulation LVO at Oita University Hospital and Nagatomi Neurosurgery Hospital from January 2014 to December 2020.

RESULTS

Age, National Institutes of Health Stroke Scale (NIHSS) score, and D-dimer concentration on admission were significant univariate prognostic factors related to mRS score 3 months after stroke onset. Multivariate logistic regression analysis showed that D-dimer concentration was the only significant independent prognostic factor. The area under the receiver operating characteristic curve for D-dimer concentration and mRS score at 3 months was 0.715 (95% confidence interval, 0.599 - 0.831); sensitivity and specificity were 60.6% and 80.0%, respectively, using a 1.9 μg/mL cutoff value.

CONCLUSIONS

Prognosis may be worse in patients undergoing acute endovascular cerebral thrombectomy with high D-dimer concentration on admission. Other treatment options should be considered for these patients.

Association of Stent-Retriever Characteristics in Establishing Successful Reperfusion During Mechanical Thrombectomy : Results from the ESCAPE-NA1 Trial

BACKGROUND

Successful reperfusion determines the treatment effect of endovascular thrombectomy. We evaluated stent-retriever characteristics and their relation to reperfusion in the ESCAPE-NA1 trial.

METHODS

Independent re-scoring of reperfusion grade for each attempt was conducted. The following characteristics were evaluated: stent-retriever length and diameter, thrombus position within stent-retriever, bypass effect, deployment in the superior or inferior MCA trunk, use of balloon guide catheter and distal access catheter. Primary outcome was successful reperfusion defined as expanded thrombolysis in cerebral infarction (eTICI) 2b-3 per attempt. The secondary outcome was successful reperfusion eTICI 2b-3 after the first attempt. Separate regression models for each stent-retriever characteristic and an exploratory multivariable modeling to test the impact of all characteristics on successful reperfusion were built.

RESULTS

Of 1105 patients in the trial, 809 with the stent-retriever use (1241 attempts) were included in the primary analysis. The stent-retriever was used as the first-line approach in 751 attempts. A successful attempt was associated with thrombus position within the proximal or middle third of the stent (OR 2.06; 95% CI: 1.24-3.40 and OR 1.92; 95% CI: 1.16-3.15 compared to the distal third respectively) and with bypass effect (OR 1.7; 95% CI: 1.07-2.72). Thrombus position within the proximal or middle third (OR 2.80; 95% CI: 1.47-5.35 and OR 2.05; 95% CI: 1.09-3.84, respectively) was associated with first-pass eTICI 2b-3 reperfusion. In the exploratory analysis accounting for all characteristics, bypass effect was the only independent predictor of eTICI 2b-3 reperfusion (OR 1.95; 95% CI: 1.10-3.46).

CONCLUSION

The presence of bypass effect and thrombus positioning within the proximal and middle third of the stent-retriever were strongly associated with successful reperfusion.

Preprocedural Prediction of Underlying Atherosclerotic Lesions in Cerebral Large-Vessel Occlusions: Clinical Backgrounds, Radiological Findings, and Treatment Outcomes

AIMS

Mechanical thrombectomy using a standard device has been effective for acute cerebral large-vessel occlusions, particularly those due to cardiogenic embolism. However, evidence for those with underlying atherosclerotic lesions is lacking. In this study, we evaluated the predictive factors, treatment details, and outcomes of acute cerebral large-vessel occlusions with underlying atherosclerotic lesions in patients who underwent mechanical thrombectomy.

METHODS

We retrospectively analyzed consecutive patients with acute large-vessel occlusions who underwent mechanical thrombectomy at our institution between August 2014 and May 2021. Predictive factors of underlying atherosclerotic lesions were evaluated using univariate and multivariate analyses. In addition, treatment details and outcomes were evaluated and compared with those of other etiologies.

RESULTS

Among 322 included patients, 202 (62.7%) were males and 65 (20.2%) had underlying atherosclerotic lesions. Multivariate analysis identified dyslipidemia, lack of arterial fibrillation documented on admission, smoking, internal carotid artery lesions, and stenosis ≥ 25% in non-occluded large vessels as predictive factors of underlying atherosclerotic lesions. Regarding treatment for underlying atherosclerotic lesions, the need for percutaneous transluminal angioplasty, stent placement, medical therapy, and longer procedure time were observed, while successful reperfusion rates, favorable outcomes, and mortality rates showed no significant differences with those of other etiologies.

CONCLUSION

Coexisting diseases and radiological findings were useful for predicting underlying atherosclerotic lesions. Further understanding these characteristics may lead to the early detection of underlying atherosclerotic lesions, optimal treatment strategies, and better outcomes.

A new constitutive model for permanent deformation of blood clots with application to simulation of aspiration thrombectomy

As a first line option in the treatment of acute ischemic stroke (AIS), direct aspiration is a fast and effective technique with promising outcomes. In silico models are widely used for design and preclinical assessment of new developed devices and therapeutic methods. Accurate modelling of the mechanical behaviour of blood clot is a key factor in the design and simulation of aspiration devices. In this study we develop a new constitutive model which incorporates the unrecoverable plastic deformation of clots. The model is developed based on the deformation-induced microstructural changes in fibrin network, including the formation and dissociation of the cross-links between fibrin fibres. The model is calibrated using previously reported experimentally measured permanent clot deformation following uniaxial stretching. The calibrated plasticity model is then used to simulate aspiration thrombectomy. Results reveal that inclusion of permanent plastic deformation results in ∼ 15 % increase in clot aspiration length at an applied aspiration pressure of 100 mmHg. The constitutive law developed in this study provides a basis for improved design and evaluation of novel aspiration catheters leading to increased first-pass revascularization rate.