A Direct Aspiration First Pass Technique Research Articles

Standardized approach to direct first pass aspiration technique for endovascular thrombectomy: Description and initial experience with CANADAPT

Background Endovascular thrombectomy (EVT) is standard of care for acute ischemic stroke. Stent assisted EVT with aspiration (SOLUMBRA) technique has remained a mainstay approach. There is growing evidence that A Direct Aspiration First Pass Technique (ADAPT) is a safe, efficient and effective approach for EVT, offering several advantages. This study describes and reports initial institutional experience in the use of a standardized scientific based aspiration only technique: CANADAPT. Methods Single center prospective cohort study was performed on consecutive patients treated for large/medium vessel ischemic stroke with CANADAPT. Intravenous thrombolytics were administered according to routine practice, independent of the decision to proceed with EVT. A sequential stepwise aspiration only technique was then applied, CANADAPT, consisting of three maneuvers, A, B and C. The reperfusion success rate, number of passes, use of rescue technique, complication rate and procedural cost were determined. Results Twenty-two patients were included in this case series representing M1 (17, 77%), M1/2 (2, 9%), carotid-T (2, 9%) and basilar (1, 5%) occlusions. First pass recanalization was achieved in 11 (50%) of patients. A further four patients had successful reperfusion with a second pass of CANADAPT (total 68% success rate). Only one patient had successful reperfusion with the aspiration catheter at the clot interface (CANADAPT A). All others required some withdrawal of the aspiration catheter for reperfusion (CANADAPT B and C). Seven patients had SOLUMBRA rescue. Of these, five patients (22% of total patients) had further successful reperfusion. Overall median procedural time was 23 min for first recanalization and 30 min for final recanalization. The cost per procedure was $6630 ± 1069 for CANADAPT, and $13,530 ± 2706 for SOLUMBRA techniques. Conclusions CANADAPT represents a standardized scientific-based approach to aspiration only thrombectomy intervention. This initial study demonstrates the safety, efficiency and efficacy of this technique for use in EVT.

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

A direct-aspiration first-pass technique (ADAPT) in mechanical thrombectomy has been described in recent studies as an efficacious strategy compared with using a stent retriever (SR). We sought to evaluate for cost differences of ADAPT technique versus SR as an initial approach. We conducted a retrospective analysis of consecutive patients with mechanical thrombectomy at our institution between 2022 and 2023. Patients were grouped into ADAPT with/without SR as a rescue strategy and SR as an initial approach with allowance of concomitant aspiration. Direct cost data (consumables) were obtained. Baseline demographics, stroke metrics, procedure outcomes and cost, and last follow-up outcomes in modified Rankin Scale were compared between 2 groups. Fifty-six patients were included. Thirty-seven (66.1%) underwent ADAPT, with 11 (29.7%) eventually requiring an SR. Mean age was 64.8 years. The average National Institutes of Health Stroke Scale score was 13.2 in the ADAPT group and 14.0 in the SR group (P= 0.68), with a similar proportion of tissue plasminogen activator (P= 0.53), site of occlusion (P= 0.66), and tandem occlusion (P= 0.69) between the groups. Recanalization was achieved in 94.6% of all patients, with an average of 1.9 passes, 89.3% being TICI 2B or above, with no differences between the 2 groups. Significantly lower cost (P < 0.01) was observed in ADAPT ($14,243.4) compared with SR ($19,003.6). Average follow-up duration was 180.2 days, with mortality of 23.2%. At last follow-up, 55.4% remained functionally independent (modified Rankin Scale score <3) with no difference (P= 0.56) between the ADAPT (59.5%) and SR (47.4%) groups. Outcomes were comparable between the ADAPT and SR groups. ADAPT reduced procedural consumables cost by approximately $5000 (25%), even if stent retrievers were allowed to be used for rescue. Establishing ADPAT as initial approach may bring significant direct cost savings while obtaining similar outcomes.

Coronary balloon-assisted navigation of aspiration catheter for stroke thrombectomy.

In recent years, A Direct Aspiration First Pass Technique (ADAPT) has emerged as an effective and safe method of thrombectomy. Large trials have shown noninferiority of ADAPT compared to primary stent retriever approach, while new studies emphasize on its shorter procedural time with potentially fewer complications and costs.1,2. Failure of the A Direct Aspiration First Pass Technique (ADAPT) is often due to the inability to successfully navigate the aspiration catheter to the thrombus site. As a solution, several techniques have been considered such as the use of stiffer microcatheters or a wedge device.3 In Video 1, we present our technique of navigating aspiration catheters with the assistance of coronary balloons. This technique has been very successful in our experience of about 30 cases in the past 6 months. Thanks to its safety and efficacy, this technique has dramatically changed our technical management of acute ischemic stroke. It can increase the ADAPT success rate while potentially reducing procedural costs.

Abstract 197: Mechanical Thrombectomy Of Basilar Artery Occlusion On A Hypoplastic Vertebrobasilar Circulation

Introduction Basilar artery occlusion (BAO) is one of the most severe acute ischemic strokes which carries high mortality and morbidity risk. Mechanical thrombectomy (MT) has been used as a promising treatment for BAO. However, the vertebral‐basilar anatomy is more challenging for MT compared to the anterior circulation due to several congenital variants such as hypoplastic vertebral artery, fenestration on the vertebrobasilar junction, or chronic asymptomatic occlusions of vertebral arteries, and tortuous subclavian arteries and vertebral arteries (VAs). Here, we described a BAO case with hypoplastic vertebrobasilar arteries, which was successfully treated with thrombectomy using the direct aspiration technique. Methods Electronic Medical Records review of a patient with acute basilar artery occlusion stroke. Results 55‐year‐old healthy gentleman presented to ER with acute onset with confusion, dysarthria, left‐sided weakness, and right facial droop. Initial NIHSS was 12. CT angiography (CTA) head and neck showed basilar artery was occluded in the distal one third segment. Because of the right fetal posterior cerebral artery and prominent left posterior communicating artery, his bilateral VAs and basilar artery were underdeveloped. The left VA appeared to be slightly bigger than the right one. After the patient received IV tPA, he was taken for mechanical thrombectomy. A Ballast catheter was placed in the left subclavian artery near the left VA origin. The conventional angiography showed the left VA was 2.8 mm and proximal basilar was about 2.1 mm. The Zoom 35 aspiration catheter was then used for mechanical thrombectomy. A complete basilar recanalization was achieved on the first pass. The patient improved after the MT. His NIHSS on discharge was 0. Conclusion The benefits of MT on BAO remain unknown despite several clinical trials. One of the reasons is due to more challenged vascular anatomy compared to anterior circulation. Underdevelopment of unilateral VA was commonly seen in posterior circulation ischemic strokes. But the underdevelopment of bilateral VAs with basilar arteries in BAO cases was rare and more difficult to treat. The Zoom 35 aspiration catheter provided a great advantage for this case with its smaller outer diameter, good navigation ability, and great aspiration efficacy. Our experience suggested a direct aspiration first pass technique (ADAPT) has an advantage on BAO, especially in the congenitally underdeveloped vertebrobasilar arteries.

Endovascular thrombectomy first-pass reperfusion and ancillary device placement

BackgroundRecent randomized trials have demonstrated the efficacy of mechanical thrombectomy in treating acute ischemic stroke, however, further research is required to optimize this technique. We aimed to evaluate the impact...

Initial Results of a Direct Aspiration First-Pass Technique to Treat Acute Ischemic Stroke Patients in Nepal.

Objective  Endovascular therapy has become the mainstay of treatment of acute ischemic stroke (AIS) due to large vessel occlusion. A direct aspiration first-pass technique (ADAPT) using large bore aspiration catheters has been introduced as a rapid, simple method for achieving good revascularization and good clinical outcomes. The aim of this study was to assess the safety and efficacy of ADAPT in the treatment of AIS due to large-vessel occlusion in the Nepali patient population. Materials and Methods  Retrospective data were collected for all consecutive patients treated for AIS with ADAPT from March 2019 through January 2021 at two hospitals. Outcomes were successful revascularization (modified thrombolysis in cerebral infarction score of 2b-3), time to revascularization, procedural complications, and good clinical outcome (modified Rankin Scale score of 0 to 2) and mortality at 90 days. Statistical Analysis  Retrospective data were collected and descriptive statistics were calculated. Results  Sixty-eight patients treated for AIS with ADAPT were included. The median National Institutes of Health Stroke Scale score at presentation was 13 (IQR 10-13.25). The median time from arterial puncture to revascularization was 40 minutes (IQR 30-45). Successful revascularization was achieved in 54 patients (79.4%). No cases of symptomatic intracranial hemorrhage occurred. At 90-day follow-up, good clinical outcome was achieved in 57 patients (83.8%), and 4 patients died (5.9%). Conclusion  A direct aspiration first pass technique appears to be a fast, simple, safe, and effective method for the management of AIS in the Nepali patient population.

Comparison of a direct aspiration first pass technique vs. stent retriever thrombectomy for the treatment of acute large vessel occlusion stroke in the anterior circulation with atrial fibrillation.

The stent retriever thrombectomy (SRT) and a direct aspiration first-pass technique (ADAPT) are the two main mechanical thrombectomy (MT) techniques for acute ischemic stroke. Few data are available for comparing the therapeutic effects associated with the two mechanical thrombectomy techniques in acute ischemic stroke with atrial fibrillation. The purpose of this study was to compare the efficacy and safety of both techniques for the treatment of acute large vessel occlusion stroke in the anterior circulation with atrial fibrillation. Retrospective analysis was performed in stroke patients with atrial fibrillation admitted to Guangzhou Red Cross Hospital from January 2018 to June 2022 who received mechanical thrombectomy by either SRT or ADAPT. Comparisons were made with regards to the initial traits, course of therapy, effectiveness indicators, and complications of these individuals. The primary outcome is recanalization rate. In this study, after screening 431 patients, 92 eligible patients, with 48 patients received SRT and 44 patients received ADAPT, were included. There was no significant difference in the recanalization rate between the two groups (SRT 87.5% vs. ADAPT 84.1%, P = 0.639). Compared with SRT, patients in ADAPT group had a shorter puncture to recanalization time [33.5 min (27.0-59.5) vs. 50.5 min (31.5-91.5), P = 0.009], a higher first pass success recanalization rate (54.5 vs. 33.3%, p = 0.040), and a higher rate of patients with improvement of NIHSS scores ≥4 at discharge (84.1 vs. 56.3%, P = 0.004). However, distal embolization occurred more frequently in the ADAPT group than that in SRT group (50.0 vs. 22.9%, P = 0.007). There was no significant difference between the two groups in the 3-month mRS score, symptomatic cerebral hemorrhage, or mortality. Compared with SRT, ADAPT has similar recanalization rate for the treatment of acute large vessel occlusion stroke in the anterior circulation with atrial fibrillation. However, ADAPT might be more effective in terms of shorter puncture to recanalization time and higher first pass success recanalization rate. Further studies are needed for confirming our results.

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

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). 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. 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%. 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.

Abstract 98: The Impact Of Aspiration Catheter Size On Thrombectomy Outcomes Using Adapt Technique-analysis From The STAR Registry

Introductions: Clinical trials have shown that aspiration thrombectomy is as safe and effective as stent-retriever thrombectomy. Multiple improvements have been made to the aspiration technique over the last few years. In this study, we aim to assess the effect of aspiration catheter bore size on the outcomes of A direct aspiration first pass technique (ADAPT) thrombectomy. Methods: We included patients who underwent ADAPT thrombectomy for M1 or internal carotid artery terminus (ICA-T) occlusions in the Stroke Thrombectomy and Aneurysm (STAR) database. Patients included between July 2016 and July 2022. We compared baseline characteristics, procedural metrics and outcomes between patients who underwent thrombectomy using small bore (0.035”-0.060”), medium bore (0.062”-0.068”) and large bore (0.070”-0.074”) catheters. Results: A total of 1158 patients were included; 576 (49.7%) females, 645 (70%) White, and 464 (40.6%) received IV-tPA. No difference was noticed in age, sex, and vascular risk factors between the 3 different groups. There was higher rate of IV-tPA in the small-bore catheter group (48.8%) compared to the medium and large bore catheter groups (38.4% and 36.7%, respectively) (P=0.03). Procedure duration was shorter when using medium (20 min) and large (18 min) compared to small bore catheters (30 min) (P=0.01). Both medium and large bore catheters were associated with higher rate of successful recanalization (88.9% and 87.9%, respectively) compared to small bore catheters (81.6%) (P=0.010). However, the difference in successful recanalization or procedure duration between medium and large bore catheters was not significant. No difference was noted in the rate of symptomatic hemorrhagic transformation (sICH) (4.7%, 5.3%, and 7.1%; P=0.345), 90-day favorable outcome (modified Rankin Scale 0-2) (41.8%, 39.3%, 40.8%; P=0.766) or 90-day mortality (18.1%, 23.5%, 24.4%; P=0.111) between the groups. Conclusions: Higher rate of successful recanalization and shorter procedure duration were observed when using medium and large bore aspiration catheters compared with small bore catheters in ADAPT technique. However, these procedural benefits were not observed when comparing large bore to medium bore catheters.

Risk factors and predictors of intracranial hemorrhage after mechanical thrombectomy in acute ischemic stroke: insights from the Stroke Thrombectomy and Aneurysm Registry (STAR)

BackgroundReducing intracranial hemorrhage (ICH) can improve patient outcome in acute ischemic stroke (AIS) intervention. We sought to identify ICH risk factors after AIS thrombectomy.MethodsThis is a retrospective review of the...

Technical note and first results on JET 7 thromboaspiration device for T-ICA occlusions

BackgroundTo describe technical features and initial results of a novel large-bore reperfusion catheter as first thromboaspiration approach for endovascular stroke treatment in terminal internal carotid artery (T-ICA) occlusions.MethodsAll patients treated with A Direct Aspiration first-Pass Technique (ADAPT) using JET 7 “Standard Tip” Penumbra Reperfusion catheter for acute T-ICA occlusion were retrospectively included in the study. Baseline data, puncture to recanalization time, number of attempts, switch to second device/technique rate and successful recanalization rate were assessed. Successful recanalization was defined by a thrombolysis in cerebral infarction (TICI) score ≥ 2b and favorable functional outcome was defined according to modified Rankin scale (score, 0–2). Catheter specifics and thromboaspiration reperfusion technique with JET 7 were reported.ResultsA total of 21 patients who underwent ADAPT with JET 7 Reperfusion catheter were enrolled for the final analysis. ADAPT was performed as first approach in all cases (100%). First attempt successful recanalization (eTICI ≥2b) was obtained in 90,5% of cases. Mean puncture to recanalization time was 16 minutes. Final successful recanalization was reached in 96.5%. Functional independence at 90 was achieved in 57,1% cases. Symptomatic intracranial hemorrhage occurred in one patient within 24 h.ConclusionThe large-bore JET 7 reperfusion catheter could be considered as first-line in patients with acute T-ICA occlusion, allowing rapid recanalization and low rate of rescue therapy with stent retriver. Further series and/or trial evaluation are required to confirm our results.

JET 7 catheter for direct aspiration in carotid T occlusions: preliminary experience and literature review.

We report our preliminary experience with the Penumbra JET 7 reperfusion catheter (JET 7), a new large-bore (0.072″) aspiration catheter, in patients with acute ischemic stroke (AIS) due to carotid T occlusion. Data of all eligible patients who received A Direct Aspiration First Pass Technique (ADAPT) for AIS due to carotid T occlusion at our center from March 2018 through June 2020 were retrospectively reviewed. The safety and performance of JET 7 cases and smaller large-bore catheters (LBCs) were compared. JET 7 was used in 19 patients, and smaller LBCs were used in 41 patients. Median puncture to revascularization time was significantly different between the JET 7 and the smaller LBCs (16 vs. 27min; P = 0.011). The rate of patients who received rescue therapy with a stent retriever was also significantly different between the JET 7 cases and the smaller LBCs cases (5.3% vs. 22.0%; P = 0.046). Successful revascularization (TICI ≥ 2b) was achieved in 94.7% of JET 7 cases and 75.6% of smaller LBCs cases (P = 0.148). Good functional outcome (mRS 0-2) at 90days occurred in 63.2% of JET 7 cases and 46.3% of smaller LBCs cases (P = 0.274). In this early experience, ADAPT with JET 7 could be considered as one of the possible first-line therapies in carotid T occlusion, showing good rate of vascularization and lower rate of rescue therapy in comparison with smaller LBCs.

Effect of Pathogenesis-Based Individualized Thrombectomy on Treatment Result and Prognosis of Acute Intracranial Large-Artery Occlusion Patients.

To explore the effect of pathogenesis-based individualised thrombectomy on the clinical results and prognoses of acute intracranial large-artery occlusion. A total of 151 patients were included in this prospective study and divided into the control group (stent thrombectomy, 53 cases), a direct aspiration first pass technique (ADAPT) group (52 cases) and the stent group (stent thrombectomy or a combination of stent thrombectomy and ADAPT, 46 cases) based on whether stent or ADAPT was used. We compared and analysed the patients? general information, the National Institutes of Health Stroke Scale (NHISS) score at admission, the time between the end of arteriography and revascularisation, the number of thrombectomies, the modified Rankin scale (mRS) score at three months and complications in the three groups. Compared with the control group, the time between the end of arteriography and revascularisation in the ADAPT group was significantly reduced (p < 0.05), and the patency rate after one thrombectomy significantly increased (p < 0.05). The positive prognosis rate was significantly increased in the stent and ADAPT groups compared with the control group (p < 0.05). The application of the ADAPT technique in patients with embolism-induced cerebral infarction can reduce the time of revascularisation. The use of stents in patients with atherosclerosis-induced cerebral infarction can increase the patency rate after one thrombectomy.

Should the direct aspiration first pass technique be advocated over the stent-retriever technique for acute ischemic stroke? A systematic review and meta-analysis of 7692 patients.

Background: The present meta-analysis aimed to synthesize evidence from all published studies with head-to-head data on the outcomes of a direct aspiration first pass technique (ADAPT) and the stent-retriever (SR) in acute ischemic stroke (AIS) patients.Methods: We searched PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials from inception to March 2021 for relevant clinical trials and observational studies. Eligible studies were identified, and all relevant outcomes were pooled in the meta-analysis random-effects model of DerSimonian-Laird.Results: Thirty studies were included in the meta-analysis with a total of 7868 patients. Compared with the SR, the ADAPT provides slightly higher rates of successful recanalization (RR 1.06, 95% CI [1.02 to 1.10]) and complete recanalization (RR 1.20, 95% CI [1.01 to 1.43]) but with more need for rescue therapy (RR 1.81, 95% CI [1.29 to 2.54]). There were no significant differences between the two techniques in terms of mortality at discharge, mortality at 90 days, change in the National Institutes of Health Stroke Scale score, the favorable outcome (modified Rankin scale (mRS) of 0-2), time to the groin puncture, or frequency of complications as intracerebral hemorrhage (ICH), symptomatic intracranial hemorrhage (sICH), embolus in a new territory (ENT), hemorrhagic infarction, parenchymal hematoma, subarachnoid hemorrhage, or procedural complications (all P > 0.05).Conclusion: Current evidence supports the use of the ADAPT technique to achieve successful and complete recanalization while considering the higher need for rescue therapy in some patients.

Abstract 1122‐000073: Influence of Catheter Tip Position and Aspiration Technique on ADAPT Revascularization Success with Various Catheters

Introduction : Previous studies demonstrated that both the location of the distal access catheter tip and angle of aspiration have a significant impact on revascularization outcomes 1,2 . A direct aspiration First‐Pass technique (ADAPT) with large‐bore aspiration catheters has emerged as a fast, safe, and effective thrombectomy technique. Maximizing the catheter‐to‐vessel size has previously been shown to enhance distal flow control resulting in improved in‐vitro revascularization rates for aspiration thrombectomy 3 . However, physicians differ in their preference for aspiration catheter tip placement, typically either positioning the catheter tip at the ‘face’ of the clot or advancing the catheter tip into the clot to engage it. We hypothesize that sizing the aspiration catheter outer diameter (OD) to the inner diameter (ID) of the vessel and embedding the catheter tip in the clot may result in ‘pinning’ fragments of clot between the catheter and vessel wall, thereby negatively affecting revascularization outcomes. Withdrawal of the aspiration catheter under continuous aspiration may mitigate this effect. We investigate the influence of catheter tip position and aspiration technique on ADAPT revascularization success with various sizes of aspiration catheters. Methods : Two clot analogues phenotypes (RBC‐Rich and Fibrin/Platelet‐Rich) were created from human blood and used to form occlusions in an In‐vitro thrombectomy model as previously described 4 . Two catheter tip positions and three techniques were investigated; 1). Catheter tip proximal to the face of the clot followed by conventional aspiration, 2). Catheter tip ‘embedded’ into the clot followed by conventional aspiration, and 3). Catheter tip ‘embedded’ into the clot followed by conventional aspiration and aspiration on catheter withdrawal even if clot ingestion occurred. Two aspiration catheters were investigated; Millipede 088’’ (Perfuze Ltd) and SOFIA Plus (Terumo). Multiple replicates of each test were performed. Endpoints were First‐Pass Effect and procedural‐related distal emboli from 200–1000µm. Results : Maximizing the catheter‐to‐vessel size increases success of the ADAPT approach when the tip is located proximal to the clot face (Fig 1 A&amp;B); Millipede 088 achieves a higher First‐Pass Effect rate than SOFIA Plus. Sizing the catheter‐to‐vessel and embedding the catheter tip into the clot (Figure 1C) results in ‘pinning’ of clot fragments between the catheter and vessel wall (Figure 1D) resulting in lower rates of First‐Pass Effect. Withdrawing the catheter under continuous aspiration increases the success of the embedding method by capturing ‘pinned’ fragments. Conclusions : The position of the aspiration catheter tip and aspiration technique used both influence the success of ADAPT procedures. Sizing the catheter‐to‐vessel results in improved revascularization. However, embedding the tip into the clot when the vessel is similar in ID to the catheter OD may reduce First‐Pass Effect rates. To optimize the rates of First‐Pass Effect, aspiration catheters may be positioned at the proximal face of the clot or retracted under continuous aspiration if wedged into the clot.

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

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

Efficacy of a Direct Aspiration First-Pass Technique (ADAPT) for Endovascular Treatment in Different Etiologies of Large Vessel Occlusion: Embolism vs. Intracranial Atherosclerotic Stenosis

Background and Aims: Aspiration thrombectomy is an effective method of recanalizing large vessel occlusion (LVO). However, the efficacy of a direct aspiration first-pass technique (ADAPT) for recanalization of LVO of different etiologies is not properly understood.Methods: The prospectively collected database on ADAPT was reviewed retrospectively. We defined two groups of enrolled patients: the embolism-related occlusions (EMB-O) group and the intracranial atherosclerotic stenosis (ICAS)-related occlusion (ICAS-O) group. Baseline characteristics, procedural variables, and post-procedural variables were collected. Multivariate logistic regression analysis was used to identify first-pass recanalization predictors.Results: Of 114 registered patients, 94 were eligible for this study (51 patients in the EMB-O group and 43 patients in the ICAS-O group). Achieving successful reperfusion immediately after direct aspiration was more frequent in the EMB-O group than in the ICAS-O group (64.71 vs. 27.91%, respectively, p = 0.006), with fewer additional rescue treatments needed (35.29 vs. 70.09%, respectively, p = 0.001). The EMB-O group also showed a higher final successful reperfusion rate (96.8 vs. 74.41%, p = 0.006). However, the 90-day good functional outcomes were not affected by the groups. Independent predictors of first-pass success of aspiration included the isolated middle cerebral artery site of occlusion, embolic etiology, and use of larger bore catheters.Conclusions: The efficacy of ADAPT recanalization approach was better in EMB-O than in ICAS-O. In case of embolic etiology and the isolated MCA site of occlusion, using a larger aspiration catheter for direct aspiration thrombectomy may be reasonable.

Abstract P504: Outcomes and Predictors of Successful First Pass in MCA Occlusions Using ADAPT Thrombectomy Technique - Insights From STAR

Introduction: Successful first pass (SFP) has been identified as a key benchmark of the success of mechanical thrombectomy (MT). However, studies that evaluate the predictors and outcomes of SFP using ADAPT (A Direct Aspiration first Pass Technique) are limied by the small number of patients or single center design. Methods: We used data from the prospectively collected data from 28 stroke centers that are included in the Stroke Thrombectomy and Aneurysm Registry (STAR). Patients with middle cerebral artery (MCA) occlusions at the level of M1 or M2 segments were included. SFP was defined by achieving modified Thrombolysis in Cerebral Infarction (mTICI) score≥2b with a single aspiration attempt. A multivariable logistic regression analysis was used to assess the predictors of SFP and evaluate the relationship between SFP and favorable 90-day outcome (90-day modified Rankin scale ≤2). Results: Out of 6123 patients included in STAR, 1002 (16.4%) underwent MT of M1 or M2 occlusion using ADAPT technique. SFP was achieved in 390 (38.9%) patients. SFP patients were older (72 vs. 69, P=0.007), had higher Alberta Stroke Program Early CT Score (ASPECTS) on presentation (9 vs. 8, P=0.018) (Table 1). On multivariable analysis, neither age (aOR 1.006, 95% CI 0.996-1.016, P=0.252) nor ASPECTS (aOR 1.055, 95% CI 0.976-1.141, P=0.179) were independent predictor of SFP. Importantly, SFP was independently associated with favorable 90-day outcome (aOR 2.769, 95% CI 1.988-3.858, P&lt;0.001) after controlling for age, sex, ASPECTS, history of atrial fibrillation, NIHSS on presentation, onset to groin time and IV-tPA. Conclusion: In this cohort of patients with M1 or M2 occlsuion undergoing MT using ADAPT technique, patients who had SFP were older and had better ASPECTS. However, both age and ASPECTS were not independently associated with SFP. Also, patients who had SFP were almost 3 times more likely to achieve favorable 90-day outcome.

Experimental Evaluation of the Risk of Distal Embolization during Endovascular Clot Retrieval Using Various Techniques.

Background:This study was conducted to evaluate various devices and techniques for endovascular thrombectomy that can reduce the risk of intraprocedural distal embolism in a preliminary in vitro setting with different types of thrombi.Materials and Methods:Endovascular clot retrieval was performed in a vascular model with collateral circulation. White and red thrombi were prepared using whole blood collected from a pig. A Direct Aspiration First Pass Technique (ADAPT), simple stentretrieving with and without proximal flow arrest by a guiding balloon (SR [B+] and SR [B±]), the AspirationRetriever Technique for Stroke (ARTS), and A stentretrieving into an Aspiration catheter with Proximal balloon (ASAP) were performed three times, respectively. The saline samples that were collected at the distal side during each procedure were examined using a particle counter. The particles were counted and categorized into three groups based on size (100 μm).Results:SR (B−) and SR (B+) could not achieve complete retrieval of the clot, especially using the white thrombus. ASAP was the only method that was able to retrieve the clots in all attempts. In both clot types, SR (B−), SR (B+), and ARTS, which involved a temporary flow restoration through stent deployment, demonstrated the migration of a greater number of particles measuring >100 μm in size than that shown by ADAPT and ASAP.Conclusions:ASAP was the safest method in terms of intraprocedural clot migration among the five methods evaluated in this study. Temporary flow restoration through stent deployment may affect the dangerous distal clot migration.

Choosing an Effective and Safe Direct Aspiration Setup for Tortuous Anatomy in Acute Ischemic Stroke: In vitro Study in a Physiological Flow Model.

A direct aspiration first pass technique (ADAPT) is an effective thrombectomy option in patients with acute ischemic stroke. Balloon guide catheters (BGC) seem to improve the efficacy of stent retrievers and ADAPT. The last generation 6F aspiration catheters require 9F BGCs, which are rigid devices that are challenging to position in a tortuous anatomy. In this experimental study the efficacy of 6F ADAPT alone and 5F ADAPT combined with 8F BGC was evaluated. Either a fibrin rich (white) clot or an RBC rich (red) clot was placed in the M1 segment of a transparent silicon phantom. Physiological hemodynamic conditions were maintained. The clots were retrieved by 6F aspiration catheter via 8F long sheath or 5F aspiration catheter via a flexible 8F BGC. Thrombectomy was performed under direct visual control. The primary endpoints were the number of passes and the number of distal emboli. Ten experiments were made with each clot model and thrombectomy technique (n = 40). Full recanalization could be achieved in every experiment. First pass mTICI 3 could be achieved by 6F ADAPT in 80 % of red clots and 90 % of white clots. Distal emboli were caused in 10 % and 20 %, respectively. When using 5F ADAPT combined with BGC, a first pass mTICI 3 rate of 90 % in red clots and 100 % in white clots could be achieved. A 10 % rate of distal emboli occurred in both groups. In almost all experiments (both techniques), the thrombi clogged the aspiration catheter. No statistically significant differences could be found between the techniques and clot models. 6F ADAPT without BGC was as effective as 5FADAPT combined with a flexible 8F BGC, with both techniques showing high first-pass recanalization rates and low distal emboli rates. Especially in the case of a tortuous anatomy, these setups should be considered as alternatives to a rigid 9F BGC. The thrombus compositions seemed to be irrelevant in this setting. · 6F ADAPT with no BGC and 5F ADAPT with BGC were very effective and performed equally.. · Both techniques should be considered in tortuous anatomy.. · In this setting the clot composition showed no effect on the recanalization rate.. · Madjidyar J, Nerkada L, Larsen N et al. Choosing an Effective and Safe Direct Aspiration Setup for Tortuous Anatomy in Acute Ischemic Stroke: In vitro Study in a Physiological Flow Model. Fortschr Röntgenstr 2021; 193: 544 - 550.