BackgroundA repeated number of passes during mechanical thrombectomy leads to worse clinical outcomes in acute ischemic stroke. Initial experiences with the simultaneous double stent-retriever (double-SR) technique as the first-line treatment showed promising safety and efficacy results.ObjectiveTo characterize the potential benefits of using the double-SR as first-line technique as compared with the traditional single-SR approach.MethodsThree types of clot analogs (soft, moderately stiff, and stiff) were used to create terminal internal carotid artery (T-ICA=44) and middle cerebral artery (MCA=88) occlusions in an in vitro neurovascular model. Sixty-six cases were randomized into each treatment arm: single-SR or double-SR, in combination with a 0.071" distal aspiration catheter. A total of 132 in vitro thrombectomies were performed. Primary endpoints were the rate of first-pass recanalization (%FPR) and procedural-related distal emboli.ResultsFPR was achieved in 42% of the cases. Overall, double-SR achieved a significantly higher %FPR than single-SR (52% vs 33%, P=0.035). Both techniques showed similar %FPR in T-ICA occlusions (single vs double: 23% vs 27%, P=0.728). Double-SR significantly outperformed single-SR in MCA occlusions (63% vs 38%, P=0.019), most notably in saddle occlusions (64% vs 14%, P=0.011), although no significant differences were found in single-branch occlusions (64% vs 50%, P=0.275). Double-SR reduced the maximal size of the clot fragments migrating distally (Feret diameter=1.08±0.65 mm vs 2.05±1.14 mm, P=0.038).ConclusionsThis randomized in vitro evaluation demonstrates that the front-line double-SR technique is more effective than single-SR in achieving FPR when treating MCA bifurcation occlusions that present saddle thrombus.

BackgroundIn 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.MethodsWe 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.ResultsDACs 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.ConclusionsThe 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.

70%. Final eTICI 2b was 95% (median 1 pass, range 1-7). There no major complications from the procedure. The rate of SAH was low (10%). Conclusion The Neurovasc Envi is a novel stent-retriever with a good safety record and excellent rates of recanalisation including high rates of FPE.

with the first pass in 213 (54.9%) participants. The total number of passes for the target lesion was 1.9 (SD 1.3). After the first pass, a modified treatment in cerebral ischemia grade (mTICI) of 2b to 3 (mTICI 2b-3) was observed in 251 (71.1%) participants and mTICI of 2c to 3 (mTICI 2c-3) was observed in 184 (52.1%). At the final angiogram, mTICI 2b-3 was observed in 380 (97.9%) participants and mTICI 2c-3 was observed in 287 (74.0%). Results varied with clot composition, but no significant difference was detected between the clot composition subgroups for mTICI 2b-3 after the first pass (P = .55). Conclusions Clot removed during neuroendovascular procedures can differ in consistency and removability, leading to an increased focus on thrombus composition as a crucial variable for improving outcomes of ischemic stroke. In this study, good final revascularization (mTICI 2b-3 at the final angiogram) occurred after aspiration thrombectomy regardless of clot composition. Ongoing analysis of collected specimens is expected to provide valuable information regarding thrombus biology and etiology and to aid in diagnosis, prognosis, and drug development.