Abstract Number ‐ 178: Optimizing Skin to Device at Occlusion Time Utilizing A Non‐exchange Technique with Novel Steerable Microcatheter

Introduction Vascular tortuosity and difficult access to the target vessel during mechanical thrombectomy is one of the reasons for failed reperfusion. The 021 Bendit adjustable micro catheter is a torqueable microcatheter with an adjustable, 360 rotating, bendable tip. Its unique structure provides it with trackability and support allowing it to be used as a select catheter for the guide and to directly access the target vessel without a guidewire. This feature can result in significant reduction in groin puncture to recanalization time, with possible implications on patient outcomes. It is also designed to fit in a standard sized aspiration catheter and allow delivery of a stentriever device if needed. Herein we describe the first US experience in 021 Bendit adjustable microcatheter in vessel selection and intracranial navigation in patients with large vessel occlusions. Methods We describe our experience with three patients who presented with large vessel occlusions for mechanical thrombectomy in July 2022. The system with guide catheter loaded with aspiration catheter and Bendit adjustable microcatheter was used to directly select the target vessels starting at the arteriotomy site, off the aortic arch and its support was used to advance the guide catheter into the cervical segment. It was then delivered to the intracranial circulation where it was used to deliver the aspiration catheter. Results Patient A is a 73‐year‐old man with a left M1 occlusion. The Bendit microcatheter was advanced through a 071 intermediate catheter and through a 088 guide catheter and was used to select the left common carotid artery. Time between device entering the body to clot touch time of 18 minutes. Patient B is a 57‐year‐old man who presented with a left cavernous internal carotid artery occlusion. The Bendit microcatheter was advanced through a 071 intermediate catheter and a 088 guide catheter was used to successfully select the left common carotid artery.Time between device entering body and bendit being at first lesion is 3 minutes. Patient C is a 60‐year‐old woman with a basilar occlusion. A 088 guide catheter was advanced over 071 intermediate catheter which was advanced over the Bendit microcatheter into the aortic arch. The Bendit microcatheter was maneuvered to select the right subclavian artery and the right vertebral artery, the system was subsequently advanced over the Bendit microcatheter intracranially. Time between groin puncture to aspiration device at the clot was 5 minutes. Conclusions The Bendit steerable microcatheter can be used to maneuver through the aortic arch and successfully select the target vessel without an exchange and without a guidewire. This approach can dramatically reduce access to recanalization time and ultimately neurologic outcomes in patients undergoing mechanical thrombectomy. As more experience is obtained, best practices will be able to achieve consistently lower times

Abstract Number: LBA4 Platelet Function Testing and Acute Thrombotic Events in Intracranial Aneurysm Patients Undergoing Flow Diversion

Introduction Introduction The role of platelet function testing in patients with intracranial aneurysms undergoing flow diversion remains controversial with limited evidence of its influence on thrombotic outcomes. We report an observational cohort analysis evaluating the association of P2Y12 assay testing with thrombotic events in patients undergoing flow diversion. Methods We performed a retrospective review of our prospectively maintained procedural database to identify patients who underwent flow diversion between January 2020 and July 2022. One physician within our practice never performs P2Y12 assay testing. All other physicians utilize P2Y12 assay testing as part of routine practice. These two different patient cohorts were compared. Acute thrombotic events were our primary outcome. Secondary outcomes included delayed intracerebral hemorrhage, intimal hyperplasia without clinical sequalae, and transient neurologic deficits. Results We identified 150 patients who underwent flow diversion at our institution between January 2020 and July 2022. Median age was 59 years old (Interquartile range (IQR) 49–67), with 113 females (82.5%) and 24 males (17.5%). Out of 150 patients, 93 (62.0%) patients were treated by physicians who performed routine pre and postoperative testing of aspirin and Plavix assays, with subsequent adjustment of antithrombotic dosing accordingly, while 57 patients (38.0%) were treated by the single physician who prescribes aspirin and clopidogrel pre‐operatively without testing. In all, seven out of 150 patients (4.7%) had an acute thrombotic event requiring intraarterial anti‐thrombotic infusion or urgent thrombectomy, or both. Of these, six where from the 93 patient testing cohort (6.5%), and one in 57 patients non‐testing cohort (1.8%) (p = 0.2). Patients who had a thrombotic event were more likely to have underlying atrial fibrillation (28.6% vs 4.9%, p = 0.01) but otherwise had similar demographics, vascular risk factors, maximal aneurysmal diameter, and parent vessel diameter (Table 1). In a multivariable analysis adjusting for age, maximal aneurysm diameter, ruptured aneurysms, and atrial fibrillation, P2Y12 sensitivity assay testing was not significantly associated with acute thrombotic events in aneurysm patients undergoing flow diversion (Odds Ratio (OR) = 0.15, 95% Confidence Interval (CI) = 0.01‐2.67), p = 0.2). Secondary outcomes were also comparable between both groups; transient neurologic deficits were noted in 4/93 in the testing group (4.3%), and 6/57 in the non‐testing group (10%) (p = 0.14), intracranial hemorrhage occurred in only 2 patients, both in the testing group (p = 0.3), and mild intimal hyperplasia was observed in 18.3% in the testing group versus 12.3% in the non‐testing group (p = 0.33). Conclusions Platelet function testing showed no significant correlation with thrombotic events or outcomes in our cohort. The role of platelet function testing remains controversial, albeit widely used in patients undergoing flow diversion of intracranial aneurysms

Synthesis and preliminary investigations of the siRNA delivery potential of novel, single-chain rigid cationic carotenoid lipids

The success of nucleic acid delivery requires the development of safe and efficient delivery vectors that overcome cellular barriers for effective transport. Herein we describe the synthesis of a series of novel, single-chain rigid cationic carotenoid lipids and a study of their preliminary in vitro siRNA delivery effectiveness and cellular toxicity. The efficiency of siRNA delivery by the single-chain lipid series was compared with that of known cationic lipid vectors, 3β-[N-(N',N'-dimethylaminoethane)carbamoyl]-cholesterol (DC-Chol) and 1,2-dimyristoyl-sn-glyceryl-3-phosphoethanolamine (EPC) as positive controls. All cationic lipids (controls and single-chain lipids) were co-formulated into liposomes with the neutral co-lipid, 1,2-dioleolyl-sn-glycerol-3-phosphoethanolamine (DOPE). Cationic lipid-siRNA complexes of varying (+/−) molar charge ratios were formulated for delivery into HR5-CL11 cells. Of the five single-chain carotenoid lipids investigated, lipids 1, 2, 3 and 5 displayed significant knockdown efficiency with HR5-CL11 cells. In addition, lipid 1 exhibited the lowest levels of cytotoxicity with cell viability greater than 80% at all (+/−) molar charge ratios studied. This novel, single-chain rigid carotenoid-based cationic lipid represents a new class of transfection vector with excellent cell tolerance, accompanied with encouraging siRNA delivery efficiency

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<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