Direct aspiration stroke thrombectomy: a comprehensive review

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

BACKGROUND

Mechanical thrombectomy (MT) is an effective treatment for acute ischemic stroke from large vessel occlusion (LVO). While embolization to a new territory (ENT) after MT is well-documented, data on embolization in the same distal territory (EDT) are limited. Achieving modified Treatment In Cerebral Infarction (mTICI) 3 reperfusion presents significant clinical benefits over mTICI 2b/2c, necessitating strategies to reduce both ENT and EDT. Previous studies suggest higher rates of EDTs with contact aspiration compared with stentrievers. However, comprehensive comparison studies in clinical practice are scarce. This study compares the rates of overall clot emboli (OCE) between these MT strategies.

METHODS

A retrospective, multicenter observational study was conducted at four university hospitals in France from January 2015 to November 2019. Adult patients (≥18 years) with acute ischemic stroke due to LVO, treated with either contact aspiration (ADAPT, A Direct Aspiration First Pass Technique) or stentrievers, specifically using the Embotrap device to maintain sample homogeneity, were included. Digital subtraction angiography was used for imaging, with two independent, blinded reviewers assessing OCE post-first MT pass. Propensity score full matching and independent sample testing were employed to evaluate OCE after the first MT pass.

RESULTS

A significant difference in OCE rates was observed between contact aspiration and stentriever techniques, with the stentriever technique resulting in fewer embolic events compared with ADAPT, based on a propensity score analysis that accounts for key confounding factors.

CONCLUSION

A statistically significant reduction in embolic events was observed with the stentriever technique compared with contact aspiration. These results suggest that the stentriever method may offer a safer profile in terms of embolic risk for LVO interventions, and should be considered over contact aspiration when embolic risk is a primary concern, while also considering individual patient factors.

Anesthetic Management for Aspiration Thrombectomy Using the Penumbra Indigo System in Pediatric Patients with Congenital Heart Disease

OBJECTIVE

To describe clinical characteristics and outcomes, including transfusion requirements, in pediatric patients with congenital heart disease undergoing aspiration thrombectomy.

DESIGN

Retrospective chart review.

SETTING

Quaternary academic children's hospital.

PARTICIPANTS

Patients aged <18 years with congenital heart disease undergoing aspiration thrombectomy between November 2017 and February 2022.

MEASUREMENTS AND MAIN RESULTS

Thirteen patients underwent mechanical thrombectomy with the Penumbra Indigo System. Their median age was 3.8 years, and median weight was 15.2 kg. Seven patients had palliated single ventricle circulation, and 6 had biventricular circulation. Nine patients had intensive care unit (ICU) admission before the procedure, and 12 required ICU admission after the procedure. Indications for thrombectomy included systemic venous thrombus in 7 patients, pulmonary arterial thrombus in 3 patients, systemic arterial thrombus in 2 patients, and systemic-to-pulmonary shunt occlusion in 1 patient. The median estimated blood loss was 7.7 mL/kg (interquartile range [IQR], 1.4-15.8 mL/kg; range, 0.5-51.5 mL/kg). Seven patients required intraoperative transfusion of packed red blood cells (n = 4), fresh frozen plasma (n = 2), platelets (n = 3), and/or cryoprecipitate (n = 1). In the patients requiring transfusion, the median transfusion volume was 22 mL/kg (IQR, 14.1-59.7 mL/kg, 9.3-132.8 mL/kg). Thrombectomy was successful in 8 of 13 patients, although 3 of these 8 patients experienced recurrent thrombosis.

CONCLUSIONS

Mechanical aspiration thrombectomy is being increasingly used to treat critically ill pediatric patients and presents unique anesthetic considerations, particularly related to the need for volume and blood product resuscitation.

The Vecta 46 intermediate catheter for mechanical thrombectomy of distal medium vessel occlusions: A single-center experience

INTRODUCTION

With emerging evidence supporting the clinical efficacy and safety of mechanical thrombectomy (MT) for distal medium vessel occlusions (DMVOs), MT devices specifically designed to navigate through smaller caliber and more delicate tortuous distal cerebrovasculature are required. This study describes our single-center experience using the AXS Vecta 46 intermediate catheter for first-line thromboaspiration of DMVOs.

METHODS

We identified all patients who underwent MT using the Vecta 46 for first-line thromboaspiration for primary or secondary DMVOs. We collected baseline clinical data, angiographic and clinical outcomes, as well as procedural complications. The primary outcome in question was the rate of successful recanalization, which was defined as a modified Thrombolysis in Cerebral Infarction score of ≥2b.

RESULTS

We identified 43 patients who underwent MT using the Vecta 46 catheter for thromboaspiration of 54 DMVOs. Intervened vessels included the M2 (23/54), M3 (19/54), and M4 (6/54) branches of the middle cerebral artery, A2 (1/54), A3 (1/54), and A4 (1/54) branches of the anterior cerebral artery, and P1 (1/54), P2 (1/54), and P4 (1/54) branches of the posterior cerebral artery. The median number of passes for primary DMVOs was 2 (IQR: 1-3) and 1 (IQR: 1-1.25) for secondary DMVOs. The rate of successful recanalization was 100% (18/18) for primary DMVOs and 80.6% (29/36) for secondary DMVOs. First-pass effect (FPE) was noted in 55.6% (30/54) of all primary and secondary DMVO cases. Improved short-term clinical outcomes were observed in both the primary (National Institute of Health Stroke Scale [NIHSS] shift: -5 [IQR: -14.25 to -0.25]) and secondary (NIHSS shift: -5 [IQR: -10 to -2]) DMVO groups. A total of six patients died during their hospitalization, though none were deemed procedural-related.

CONCLUSIONS

Our study demonstrates the safety and efficacy of the Vecta 46 intermediate catheter for thromboaspiration of both primary and secondary DMVOs, achieving high rates of successful recanalization and FPE.

Optimizing suction force in mechanical thrombectomy: Priming the aspiration tubing with air versus saline

OBJECTIVE

We sought to investigate how priming the tube between air versus air mixed with saline ex vivo influenced suction force. We examined how priming the tube influenced peak suction force and time to achieve peak suction force between both modalities.

METHODS

Using a Dwyer Instruments (Dwyer Instruments Inc., Michigan City, IN, USA), INC Digitial Pressure Gauge, we were able to connect a .072 inch aspiration catheter to a rotating hemostatic valve and to aspiration tubing. We recorded suction force measured in negative inches of Mercury (inHg) over 10 iterations between having the aspiration tube primed with air alone versus air mixed with saline. A test was used to compare results between both modalities.

RESULTS

Priming the tube with air alone compared to air mixed with saline was found to have an increased average max suction force (-28.60 versus -28.20 in HG, p<0.01). We also identified a logarithmic curve of suction force across time in which time to maximal suction force was more prompt with air compared with air mixed with saline (13.8 seconds versus 21.60 seconds, p<0.01).

CONCLUSIONS

Priming the tube with air compared to air mixed with saline suggests that not only is increased maximal suction force achieved, but also the time required to achieve maximal suction force is less. This data suggests against priming the aspiration tubing with saline and suggests that the first pass aspiration primed with air may have the greatest suction force.

Collateral flow and pulsatility during large vessel occlusions: insights from a quantitative in vitro study

Acute ischemic stroke caused by large vessel occlusions is being increasingly treated with neurovascular interventions. The hemodynamics within the collateral system of the circle of Willis (CoW) hemodynamics play a fundamental role in therapy success. However, transient in vivo data on pathological collateral flow during large vessel occlusions are not available. Moreover, there are no flow models that accurately simulate the hemodynamic conditions in the CoW during large vessel occlusions. We used a circulatory loop to generate highly reproducible cerebrovascular-like flows and pressures and used non-invasive flow visualization and high-resolution flow and pressure measurements to acquire detailed, time-dependent hemodynamics inside an anatomical phantom of the CoW. After calibrating a physiological reference case, we induced occlusions in the 1. middle cerebral artery, 2. terminal carotid artery, and 3. basilar artery; and measured the left posterior communicating artery flow. Mean arterial pressure and pulse pressure remained unchanged in the different occlusion cases compared to the physiological reference case, while total cerebral flow decreased by up to 19%. In all three occlusion cases, reversed flow was found in the left posterior communicating artery compared to the reference case with different flow magnitudes and pulsatility index values. The experimental results were compared with clinical findings, demonstrating the capability of this realistic cerebrovascular flow setup. This novel cerebrovascular flow setup opens the possibility for investigating different topics of neurovascular interventions under various clinical conditions in controlled preclinical laboratory studies.

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.

Experimental evaluation of the plunger technique: A method of cyclic manual aspiration thrombectomy for treatment of acute ischemic stroke

BACKGROUND

Mechanical thrombectomy via direct aspiration is a rapid treatment for acute ischemic stroke. This method often results in the partial ingestion of the clot or "corking" of the catheter tip. Cyclic aspiration may take advantage of the mechanical properties of the clot, resulting in greater clot ingestion and overall procedure success.

METHODS

An in vitro analysis was performed comparing static and cyclic (plunger technique) aspiration. Embolus analogs were used to create occlusions in a mock circulatory flow loop, and one aspiration attempt (first pass effect) using either a static or plunger technique was performed. The percent ingestion of each embolus analog was recorded for each trial.

RESULTS

Static aspiration for 0% and 50% hematocrit embolus analogs resulted in ingestions of 12.8 ± 4.6% and 15.1 ± 10.0%, respectively, while plunger technique (cyclic) aspiration resulted in 15.8 ± 7.3% and 34.4 ± 19.5% ingestion. Complete ingestion was observed only with 50% hematocrit analogs, occurring in 30% of plunger and 10% of static cases. Statistical differences were determined between the two aspiration techniques for the 50% hematocrit samples, with the plunger technique yielding significantly more ingestion. In addition, the plunger technique was shown to maintain a negative vacuum pressure throughout the duration of cyclic plunging.

CONCLUSIONS

The plunger technique for manual cyclic aspiration resulted in higher rates of complete ingestion and greater average % ingestions when compared to static aspiration. Increased clot ingestion can result in a higher rate of complete reperfusion during the first aspiration attempt, maximizing the number of patients with good clinical outcomes.

First experience with Walrus balloon guide catheter in a whole-body flow model

PURPOSE

Flow arrest using a balloon guide catheter (BGC) in mechanical thrombectomy (MT) due to large vessel occlusion has been associated with better outcomes. Known limitations of currently commercially available BGCs are incompatibility with large bore aspiration catheters (AC) and lack of distal flexibility. Walrus presents variable stiffness and compatibility with large bore AC. The goal of this study is to describe the first experience with Walrus in a realistic stroke simulation model.

METHODS

A full-length modular vascular model under physiological conditions was used. 8F+-Walrus inner-diameter (ID) 0.087in 95 cm combined with 6F-Sofia AC ID 0.070in 131 cm and an 8F-Flowgate2 BGC ID 0.084in 95 cm with a 5F-Sofia AC ID 0.055in 125 cm were used to perform aspiration MT. User surveys, access to target and occlusion site, technique, time of delivery, anatomical change, and catheter kick-back were assessed.

RESULTS

Seven neuroradiologists with average of 10 years-experience in MT performed primary aspiration using the above-mentioned combinations in three different anatomies (N = 41). All operators would likely (29%) or very likely (71%) use again Walrus in combination with large bore AC and the majority (86%) found its navigability easier than with other BGCs. Time to reach final BGC position and catheter kick-back did not differ significantly among anatomies or catheter combinations (p > 0.05). However, Walrus was more likely to reach ICA petrous segment (p < 0.05) and intracranial occlusion with AC (p < 0.01).

CONCLUSION

The Walrus combined with large bore AC presented significantly better distal access and navigability for primary aspiration in an in vitro stroke model.

Use of angled-tip aspiration catheters is associated with a lower cost of thrombectomy in patients with acute ischemic stroke secondary to large and medium vessel occlusions

BACKGROUND

Recently, the angled-tip Zoom™ aspiration catheters were introduced. The tip is designed to improve suction force for clot retrieval. We evaluated the possibility of reducing procedure costs when using angled-tip catheters and compared the safety and angiographic effectiveness of angled-tip versus straight-tip catheters.

METHODS

We conducted a retrospective single-center cohort study involving patients with acute ischemic stroke due to large and medium vessel occlusions. The patients were divided into two groups: the post-Zoom group, in which angled-tip aspiration catheters were used and the pre-Zoom group, in which traditional straight-tip catheters were employed.

RESULTS

A total of 163 patients were included; 95 (58.3%) in the pre-Zoom group and 68 (41.7%) in the post-Zoom group. The groups were well-matched at entry. The post-Zoom group demonstrated a significant decrease in mean procedure cost ($9728 vs. $12,127; p = 0.002), shorter time to achieve modified thrombolysis in cerebral infarction ≥2b reperfusion (38.30 min vs. 53.26 min; p = 0.018), and shorter puncture to procedure completion time (46.42 min vs. 62.38 min; p = 0.022). Additionally, the mean procedural cost when using the ADAPT technique supported by the Zoom catheters was significantly lower than the Solumbra technique ($5754 ± $2806 vs. $13,498 ± $3244, p < 0.001). There were no differences in the rate of hemorrhage between the pre-Zoom group (17.9%) and the post-Zoom group (20.6%), p = 0.690.

CONCLUSION

The study demonstrated significant benefits, including cost reduction and shorter time to achieve reperfusion in patients treated with Zoom aspiration catheters. These findings support the use of angled-tip catheters in acute ischemic stroke management.

Distal medium vessel occlusions in acute ischaemic stroke - Stent retriever versus direct aspiration: A systematic review and meta-analysis

BACKGROUND

Acute ischaemic stroke due to distal medium vessel occlusion (AIS-DMVO) causes significant morbidity. Endovascular thrombectomy advancement has made treating AIS-DMVO with stent retrievers (SR) and aspiration catheters (AC) possible, however the optimal technique remains unknown. We performed a systematic review and meta-analysis to investigate the efficacy and safety of SR use compared to purely AC use in patients with AIS-DMVO.

METHODS

We systematically searched PubMed, Cochrane Library and EMBASE, from inception to 2nd September 2022, for studies comparing SR or primary combined (SR/PC) against AC in AIS-DMVO. We adopted the Distal Thrombectomy Summit Group's definition of DMVO. Efficacy outcomes were functional independence (modified Rankin Scale (mRS) 0-2 at 90 days), first pass effect (modified Thrombolysis in Cerebral Infarction scale (mTICI) 2c-3 or expanded Thrombolysis in Cerebral Infarction scale (eTICI) 2c-3 at first pass), successful final recanalisation (mTICI or eTICI 2b-3), and excellent final recanalisation (mTICI or eTICI 2c-3). Safety outcomes were symptomatic intracranial haemorrhage (sICH) and 90-day mortality.

RESULTS

12 cohort studies and 1 randomised-controlled trial were included, involving 1881 patients with 1274 receiving SR/PC and 607 receiving AC only. SR/PC achieved higher odds of functional independence (odds ratio (OR) 1.33, 95% confidence interval (CI) 1.06-1.67) and lower odds of mortality (OR 0.69, 95% CI 0.50-0.94) than AC. Odds of successful/excellent recanalisation and sICH were similar between both groups. Stratified to compare only SR and only AC, the use of only SR, achieved significantly higher odds of successful recanalisation as compared to only AC (OR 1.80, 95% CI 1.17-2.78).

CONCLUSION

There is potential for efficacy and safety benefits in SR/PC use as compared to AC only in AIS-DMVO. Further trials are necessary to validate the efficacy and safety of SR use in AIS-DMVO.

A multiscale computational framework to evaluate flow alterations during mechanical thrombectomy for treatment of ischaemic stroke

The treatment of ischaemic stroke increasingly relies upon endovascular procedures known as mechanical thrombectomy (MT), which consists in capturing and removing the clot with a catheter-guided stent while at the same time applying external aspiration with the aim of reducing haemodynamic loads during retrieval. However, uniform consensus on procedural parameters such as the use of balloon guide catheters (BGC) to provide proximal flow control, or the position of the aspiration catheter is still lacking. Ultimately the decision is left to the clinician performing the operation, and it is difficult to predict how these treatment options might influence clinical outcome. In this study we present a multiscale computational framework to simulate MT procedures. The developed framework can provide quantitative assessment of clinically relevant quantities such as flow in the retrieval path and can be used to find the optimal procedural parameters that are most likely to result in a favorable clinical outcome. The results show the advantage of using BGC during MT and indicate small differences between positioning the aspiration catheter in proximal or distal locations. The framework has significant potential for future expansions and applications to other surgical treatments.

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.

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.

A Review of the Advancements in the in-vitro Modelling of Acute Ischemic Stroke and Its Treatment

In-vitro neurovascular models of large vessel occlusions (LVOs) causing acute ischemic stroke (AIS) are used extensively for pre-clinical testing of new treatment devices. They enable physicians and engineers to examine device performance and the response of the occlusion to further advance design solutions for current unmet clinical needs. These models also enable physicians to train on basic skills, to try out new devices and new procedural approaches, and for the stroke team to practice workflows together in the comfort of a controlled environment in a non-clinical setting. Removal of the occlusive clot in its entirety is the primary goal of the endovascular treatment of LVOs via mechanical thrombectomy (MT) and the medical treatment via thrombolysis. In MT, recanalization after just one pass is associated with better clinical outcomes than procedures that take multiple passes to achieve the same level of recanalization, commonly known as first pass effect (FPE). To achieve this, physicians and engineers are continually investigating new devices and treatment approaches. To distinguish between treatment devices in the pre-clinical setting, test models must also be optimized and expanded become more nuanced and to represent challenging patient cohorts that could be improved through new technology or better techniques. The aim of this paper is to provide a perspective review of the recent advancements in the in-vitro modeling of stroke and to outline how these models need to advance further in future. This review provides an overview of the various in-vitro models used for the modeling of AIS and compares the advantages and limitations of each. In-vitro models remain an extremely useful tool in the evaluation and design of treatment devices, and great strides have been made to improve replication of physiological conditions. However, further advancement is still required to represent the expanding indications for thrombectomy and thrombolysis, and the generation of new thrombectomy devices, to ensure that smaller treatment effects are captured.

Use of the Rocket Technique after Failure of the Direct Aspiration First-Pass Technique in Acute Stroke Thrombectomy

The technical feasibility of the rocket technique was evaluated for patients treated for stroke where the direct aspiration first-pass technique (ADAPT) failed to reach the occlusion site. This single-center retrospective study included data on consecutive patients with a large vessel occlusion of the anterior circulation who underwent mechanical thrombectomy. Of 138 patients, 100 met the inclusion criteria. In 84 patients, a large 0.072-inch inner lumen aspiration catheter was able to reach the occlusion site when deployed with a coaxial microcatheter. In 16 patients, this technique failed, and the microcatheter was replaced with a compliant balloon inflated at the extremity of the aspiration catheter (rocket technique). In 15 of these 16 patients, the rocket technique brought the catheter into contact with the thrombus. In conclusion, when deployment of the ADAPT with a coaxial microcatheter fails to reach the clot site, the rocket technique can safely advance the aspiration catheter to the clot.

Trackability of distal access catheters: an in vitro quantitative evaluation of navigation strategies

BACKGROUND

In mechanical thrombectomy (MT), distal access catheters (DACs) are tracked through the vascular anatomy to reach the occlusion site. The inability of DACs to reach the occlusion site has been reported as a predictor of unsuccessful recanalization. This study aims to provide insight into how to navigate devices through the vascular anatomy with minimal track forces, since higher forces may imply more risk of vascular injuries.

METHODS

We designed an experimental setup to monitor DAC track forces when navigating through an in vitro anatomical model. Experiments were recorded to study mechanical behaviors such as tension buildup against vessel walls, DAC buckling, and abrupt advancements. A multiple regression analysis was performed to predict track forces from the catheters' design specifications.

RESULTS

DACs were successfully delivered to the target M1 in 60 of 63 in vitro experiments (95.2%). Compared to navigation with unsupported DAC, the concomitant coaxial use of a microcatheter/microguidewire and microcatheter/stent retriever anchoring significantly reduced the track forces by about 63% and 77%, respectively (p<0.01). The presence of the braid pattern in the reinforcement significantly reduced the track forces regardless of the technique used (p<0.05). Combined coil and braid reinforcement configuration, as compared with coil alone, and a thinner distal wall were predictors of lower track force when navigating with unsupported DAC.

CONCLUSIONS

The use of microcatheter and stent retriever facilitate smooth navigation of DACs through the vascular tortuosity to reach the occlusion site, which in turn improves the reliability of tracking when positioning the DAC closer to the thrombus interface.

Impact of Increasing Aspiration Catheter Size and Refinement of Technique: Experience of Over 1000 Strokes Treated With ADAPT

BACKGROUND

We present longitudinal data regarding the outcomes and evolution of mechanical thrombectomy (MT) using a direct aspiration first pass technique.

OBJECTIVE

To evaluate the impact of increasing aspiration catheter size.

METHODS

This is a planned analysis of a prospective cohort study that enrolled all patients who underwent a direct aspiration first pass technique MT in a comprehensive stroke center from January 2013 to December 2020. We did exploratory analysis of the characteristics and outcomes of patients who had intracranial internal carotid artery or M1 segment of middle cerebral artery occlusion based on the aspiration catheter bore size (small [041, 054, 058, and 060 inch] vs medium [0.064 and 0.068 inch] and medium vs large [0.071, 0.072, and 0.074 inch]).

RESULTS

During the 8-year study period, a total of 1004 patients were included. Median age was 69 years, 49% were female patients, and 60.6% were White. Symptomatic hemorrhagic transformation was observed in 47 patients (4.7%), and 366 patients (36.5%) achieved the modified Rankin scale of 0 to 2 at 90 days after the stroke. For patients with intracranial internal carotid artery or M1 occlusion, medium-bore aspiration catheters were more likely to achieve successful recanalization after first aspiration attempt (63.9% vs 51.4%, P = .015) and had a faster groin-to-reperfusion time (16 vs 20 minutes, P = .001) when compared with small-bore catheters. However, these differences were not significant when comparing medium-bore with large-bore catheters.

CONCLUSION

Medium-bore catheters had better performance measures compared with small-bore catheters. However, large-bore catheters did not show significantly better performance results that suggest a plateau effect.

Comparative study on treatment of acute cerebral infarction between mechanical thrombectomy by micro catheter and thrombectomy by Solitaire AB stent

BACKGROUND

Acute cerebral artery occlusion is a common disease with high morbidity and mortality. At present, the commonly used mechanical thrombectomy schemes are mechanical thrombectomy and stent thrombectomy. However, the clinical differences between the two methods is not fully understood. The present study aimed to evaluate the clinical effectiveness of Solitaire AB stent thrombectomy for acute cerebral infarction (ACI).

METHODS

A retrospective study was carried out in 96 ACI patients admitted to our department from January 2017 to January 2020. According to the treatment they received, they were divided into group A (conventional microcatheter mechanical thrombectomy, n = 48) and group B (Solitaire AB stent thrombectomy, n = 48). All patients were followed up for 3 months. Their pre- and post-operative nerve function indices were compared between the 2 groups. The therapeutic effects were evaluated by thrombolysis in cerebral infarction scale system, Glasgow coma scale (GCS), National Institutes of Health Stroke Scale (NIHSS), and modified Rankin scale statistics.

RESULTS

Two groups of patients with NIHSS scores postoperative 3 and 30 days decreased significantly compared with preoperation. NIHSS score of group A 3 and 30 days postoperation was significantly higher than group B (P < .05). Two groups of patients with GCS scores postoperative 3 and 30 days increased significantly compared with preoperation. GCS score of group A 3 and 30 days postoperation was significantly lower than group B (P < .05). Group B with vascular recanalization ratio postoperative 30 days was higher than group A, however with no significant differences (P > .05). Moreover, group B with outcomes (modified Rankin scale score ≤2 points) postoperative 3 months was better than group A, however with no significant differences (P > .05).

CONCLUSION

Solitaire AB stent embolectomy shows similar efficacy as mechanical thrombectomy in the treatment of ACI patients.

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.

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.

Predictors of Functional Outcome and Mortality in Endovascular Treatment for Acute Basilar Artery Occlusion: A Single-Centre Experience

Background and Purpose: The objective of this study was to identify prognostic factors of endovascular treatment in patients with acute basilar artery occlusion and add evidence about the efficacy and safety of endovascular treatment for acute basilar artery occlusion. Materials and Methods: We reviewed the data of 101 patients with acute basilar artery occlusion receiving endovascular treatment from January 2013 to September 2019. Baseline characteristics and outcomes were evaluated. A favourable functional outcome was defined as a mRS of 0 to 2 assessed at the 3 month follow-up. The association of clinical and procedural characteristics with the functional outcome and mortality was assessed. Results: The study population consisted of 101 patients: 83 males and 18 females. Successful recanalization was achieved in 99 patients (97.1%). A favourable clinical outcome was observed in 50 patients (49.5%), and the overall mortality rate was 26.7%. A favourable outcome was significantly associated with NIHSS score at admission and lung infection. Mortality was associated with NIHSS score at admission, the number of thrombectomy device passes, the postoperative pons-midbrain index, and diabetes mellitus. Conclusions: This study suggested that NIHSS score at admission, the number of thrombectomy device passes, the postoperative pons-midbrain index, diabetes mellitus, and lung infection can predict the functional outcome and mortality. These initial results add evidence about the efficacy and safety of endovascular treatment for acute basilar artery occlusion and need to be confirmed by further prospective studies.

Delays in presentation and mortality among Black patients with mechanical thrombectomy after large-vessel stroke at a US hospital

OBJECTIVE

The incidence and severity of stroke are disproportionately greater among Black patients. In this study, the authors sought to examine clinical outcomes among Black versus White patients after mechanical thrombectomy for stroke at a single US institution.

METHODS

All patients who underwent mechanical thrombectomy at a single center from January 1, 2014, through March 31, 2020, were retrospectively analyzed. Patients were grouped based on race, and demographic characteristics, preexisting conditions, clinical presentation, treatment, and stroke outcomes were compared. The association of race with mortality was analyzed in multivariable logistic regression analysis adjusted for potential confounders.

RESULTS

In total, 401 patients (233 males) with a reported race of Black (n = 28) or White (n = 373) underwent mechanical thrombectomy during the study period. Tobacco use was more prevalent among Black patients (43% vs 24%, p = 0.04), but there were no significant differences between the groups with respect to insurance, coronary artery disease, diabetes, illicit drug use, hypertension, or hyperlipidemia. The mean time from stroke onset to hospital presentation was significantly greater among Black patients (604.6 vs 333.4 minutes) (p = 0.007). There were no differences in fluoroscopy time, procedural success (Thrombolysis in Cerebral Infarction grade 2b or 3), hospital length of stay, or prevalence of hemicraniectomy. In multivariable analysis, Black race was strongly associated with higher mortality (32.1% vs 14.5%, p = 0.01). The disparity in mortality rates resolved after adjusting for the average time from stroke onset to presentation (p = 0.14).

CONCLUSIONS

Black race was associated with an increased risk of death after mechanical thrombectomy for stroke. The increased risk may be associated with access-related factors, including delayed presentation to stroke centers.

Cyclical aspiration using a novel mechanical thrombectomy device is associated with a high TICI 3 first pass effect in large-vessel strokes

Background and Purpose

Complete reperfusion (TICI 3) after the first thrombectomy attempt or first pass effect (FPE) is associated with best clinical outcomes in large‐vessel occlusion (LVO) acute ischemic stroke. While endovascular therapy techniques have improved substantially, FPE remains low (24–30%), and new methods to improve reperfusion efficiency are needed.

Methods

In a prospective observational cohort study, 40 consecutive patients underwent cyclical aspiration thrombectomy using CLEAR^TM Aspiration System (Insera Therapeutics Inc., Dallas, TX). Primary outcome included FPE with complete/near‐complete reperfusion (TICI 2c/3 FPE). Secondary outcomes included early neurological improvement measured by the National Institute of Health Stroke Scale (NIHSS), safety outcomes, and functional outcomes using modified Rankin Scale (mRS). Outcomes were compared against published historical controls.

Results

Among 38 patients who met criteria for LVO, median age was 75 (range 31–96). FPE was high (TICI 3: 26/38 [68%], TICI 2c/3: 29/38 [76%]). Among anterior circulation strokes, core lab‐adjudicated FPE remained high (TICI 3: 17/29 [59%], TICI 2c/3: 20/29 [69%]), with excellent final successful revascularization results (Final TICI 3: 24/29 [83%], Final TICI 2c/3: 27/29 [93%]). FPE in the CLEAR‐1 cohort was significantly higher compared to FPE using existing devices (meta‐analysis) from historical controls (TICI 2c/3: 76% vs. 28%, p = 0.0001). High rates of early neurological improvement were observed (delta NIHSS≥4: 35/38 [92.1%]; delta NIHSS≥10: 27/38 [71%]). Similarly, high rates of good functional outcomes (mRS 0–2: 32/38 [84%]) and low mortality (2/38 [5%]) were observed.

Conclusion

Cyclical aspiration using the CLEAR^TM Aspiration System is safe, effective, and achieved a high TICI 3 FPE for large‐vessel strokes.

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.

First-line thrombectomy strategy for anterior large vessel occlusions: results of the prospective ETIS egistry

BACKGROUND

The best recanalization strategy for mechanical thrombectomy (MT) remains unknown as no randomized controlled trial has simultaneously evaluated first-line stent retriever (SR) versus contact aspiration (CA) versus the combined approach (SR+CA).

OBJECTIVE

To compare the efficacy and safety profiles of SR, CA, and SR+CA in patients with acute ischemic stroke (AIS) treated by MT.

METHODS

We analyzed data of the Endovascular Treatment in Ischemic Stroke (ETIS) Registry, a prospective, multicenter, observational study of patients with AIS treated by MT. Patients with M1 and intracranial internal carotid artery (ICA) occlusions between January 2015 and March 2020 in 15 comprehensive stroke centers were included. We assessed the association of first-line strategy with favorable outcomes at 3 months (modified Rankin Scale score 0-2), successful recanalization rates (modified Thrombolysis In Cerebral Infarction (mTICI) 2b/3), and safety outcomes.

RESULTS

We included 2643 patients, 406 treated with SR, 1126 with CA, and 1111 with SR+CA. CA or SR+CA achieved more successful recanalization than SR for M1 occlusions (aOR=2.09, (95% CI 1.39 to 3.13) and aOR=1.69 (95% CI 1.12 to 2.53), respectively). For intracranial ICA, SR+CA achieved more recanalization than SR (aOR=2.52 (95% CI 1.32 to 4.81)), no differences were observed between CA and SR+CA. SR+CA was associated with lower odds of favorable outcomes compared with SR (aOR=0.63 (95% CI 0.44 to 0.90)) and CA (aOR=0.71 (95% CI 0.55 to 0.92)), higher odds of mortality at 3 months (aOR=1.56 (95% CI 1.22 to 2.0)) compared with CA, and higher odds of symptomatic intracranial hemorrhage (aOR=1.59 (95% CI 1.1 to 2.3)) compared with CA.

CONCLUSIONS

Despite high recanalization rates, our results question the safety of the combined approach, which was associated with disability and mortality. Randomized controlled trials are needed to evaluate the efficacy and safety of these techniques.

Factors influencing thrombectomy decision making for primary medium vessel occlusion stroke

BACKGROUND

We aimed to explore the preference of stroke physicians to treat patients with primary medium vessel occlusion (MeVO) stroke with immediate endovascular treatment (EVT) in an international cross-sectional survey, as there is no clear guideline recommendation for EVT in these patients.

METHODS

In the survey MeVO-Finding Rationales and Objectifying New Targets for IntervEntional Revascularization in Stroke (MeVO-FRONTIERS), participants were shown four cases of primary MeVOs (six scenarios per case) and asked whether they would treat those patients with EVT. Multivariable logistic regression with clustering by respondent was performed to assess factors influencing the decision to treat. Dominance analysis was performed to assess the influence of factors within the scenarios on decision making.

RESULTS

Overall, 366 participants (56 women; 15%) from 44 countries provided 8784 answers to 24 scenarios. Most physicians (59.2%) would treat patients immediately with EVT. Younger patient age (incidence rate ratio (IRR) 1.24, 99% CI 1.19 to 1.30), higher National Institutes of Health Stroke Scale (NIHSS) score (IRR 1.69, 99% CI 1.57 to 1.82), and small core volume (IRR 1.35, 99% CI 1.24 to 1.46) were positively associated with the decision to treat with EVT. Interventionalists (IRR 1.26, 99% CI 1.01 to 1.56) were more likely to treat patients with MeVO immediately with EVT. In the dominance analysis, factors influencing the decision in favor of EVT were (in order of importance): baseline NIHSS, core volume, alteplase use, patients' age, and occlusion site.

CONCLUSIONS

Most physicians in this survey were interventionalists and would treat patients with MeVO stroke immediately with EVT. This finding supports the need for robust clinical evidence.

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.

Walrus large bore guide catheter impact on recanalization first pass effect and outcomes: the WICkED study

BACKGROUND

The use of a balloon-guide catheter (BGC) in acute stroke treatment has been widely adopted after demonstrating optimized procedure metrics and outcomes. Initial technical constraints of previous devices included catheter stiffness and smaller inner diameters. We aim to evaluate the performance and safety of the Walrus BGC, a variable stiffness catheter with a large bore 0.087 inch inner diameter (ID), via the the WICkED study (Walrus Large Bore guide Catheter Impact on reCanalization first pass Effect anD outcomes).

METHODS

This is a retrospective, site adjudicated, multicenter study on consecutive patients with large vessel occlusion treated with the Walrus BGC. Baseline characteristics, procedural outcomes and functional outcomes were analyzed.

RESULTS

A total of 338 patients met the inclusion criteria. The Walrus was successfully tracked into distal vasculature and allowed therapeutic device delivery in all but 3 cases (0.9%). Large aspiration catheters ≥0.070 inch ID were used in 71.9% of cases. Stent retriever thrombectomy was used as the first-line modality in 59.2% and thromboaspiration in 40.8% of cases. The successful recanalization rate (modified treatment in cerebral ischemia (mTICI) 2b/3) was 94.4%, with 64.8% of the patients achieving mTICI 2b/3 after the first pass. The Walrus-related adverse event rate was 0.6%, corresponding to two vessel dissections. Functional independence was 50% (126/252) and mortality 25% (63/252). Unfavorable outcomes were more likely in older patients, who had unsuccessful reperfusion, longer procedure times, and a higher mean number of passes.

CONCLUSION

In acute ischemic stroke patients presenting with large vessel occlusion, the Walrus BGC demonstrated excellent navigability and safety profile, allowed the accommodation of leading large bore aspiration catheters, and demonstrated high vessel recanalization rates.

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.

Efficacy of beveled tip aspiration catheter in mechanical thrombectomy for acute ischemic stroke

Background

Direct aspiration thrombectomy techniques use large bore aspiration catheters for mechanical thrombectomy. Several aspiration catheters are now available. We report a bench top exploration of a novel beveled tip catheter and our experience in treating large vessel occlusions (LVOs) using next-generation aspiration catheters.

Methods

A retrospective analysis from a prospectively maintained database comparing the bevel shaped tip aspiration catheter versus non-beveled tip catheters was performed. Patient demographics, periprocedural metrics, and discharge and 90-day modified Rankin Scale (mRS) scores were collected. Patients were divided into two groups based on which aspiration catheter was used.

Results

Our data showed no significant difference in age, gender, IV tissue plasminogen activator administration, admission NIH Stroke Scale score, baseline mRS, or LVO location between the beveled tip and flat tip groups. With the beveled tip, Thrombolysis in Cerebral Infarction (TICI) 2C or better recanalization was more frequent overall (93.2% vs 74.2%, p=0.017), stent retriever usage was lower (9.1% vs 29%, p=0.024), and patients had lower mRS on discharge (median 3 vs 4, p<0.001) and at 90 days (median 2 vs 4, p=0.008).

Conclusion

Patients who underwent mechanical thrombectomy with the beveled tip catheter had a higher proportion of TICI 2C or better and had a significantly lower mRS score on discharge and at 90 days.