Development of a high-speed synchronous micro motor and its application in intravascular imaging

In this study, we demonstrate the design, fabrication and characterization of a synchronous micro motor. The micro motor consists of flex print coils and a permanent magnet rotor. The size of the motor is 2.0 mm length and 1.0 mm outer diameter. With 1.0 A effective driving current, the motor can rotate a 0.3 mm mirror at a maximum speed of 3640 revolutions per second. The uniformity and accuracy of the motor was characterized at 50 Hz, 200 Hz and 3200 Hz driving frequencies. The performance improved by increasing the driving frequency, which was represented as better speed uniformity and lower angular error. The torque of the motor was estimated to be 0.25-0.27 μN m with 1.0 A current by fitting the measured speed based on the equation of motion. We describe the application of the micro motor as a distal actuator for intravascular imaging. We constructed optical and ultrasonic imaging catheters and show the intravascular images of coronary arteries obtained with these catheters

Timing of acute carotid artery stenting for tandem lesions in patients with acute ischemic stroke:A Maastricht Stroke Quality Registry (MaSQ-Registry) study

BACKGROUND: To better understand the influence of treatment strategies on outcomes for patients with tandem lesions undergoing acute internal carotid artery (ICA) stenting during endovascular treatment (EVT), this study compared clinical, technical, and safety outcomes in patients with acute ischemic stroke due to a large vessel occlusion (LVO) who underwent ICA stenting before versus after intracranial thrombectomy. METHODS: This single-center retrospective cohort study included patients who underwent EVT due to a LVO and periprocedural ICA stenting for significant ICA stenosis or occlusion between September 2020 and January 2023. Data were extracted from the Maastricht Stroke Quality Registry (MaSQ-Registry). Primary outcome was the modified Rankin Scale (mRS) at 3 months. Secondary outcomes included procedure times, number of total thrombectomy attempts, first-attempt excellent recanalization rates (extended Thrombolysis In Cerebral Infarction (eTICI) = 2C after one thrombectomy attempt), and safety outcomes. RESULTS: This study included 50 patients. Thirty-one patients (62%) underwent ICA stenting before intracranial thrombectomy. No significant differences between both groups were found regarding mRS, total procedure time, number of total thrombectomy attempts, first-attempt excellent recanalization, or complications. Time between groin puncture and recanalization (reperfusion time) was significantly longer in patients who had ICA stenting before intracranial thrombectomy versus after intracranial thrombectomy (45 min versus 28 min, P = 0.004). CONCLUSION: ICA stenting after intracranial thrombectomy in patients with tandem lesions undergoing EVT did not lead to better patient outcomes compared to stenting before intracranial thrombectomy, despite shorter reperfusion times

Endovascular treatment versus no endovascular treatment after 6–24 h in patients with ischaemic stroke and collateral flow on CT angiography (MR CLEAN-LATE) in the Netherlands:a multicentre, open-label, blinded-endpoint, randomised, controlled, phase 3 trial

Background: Endovascular treatment for anterior circulation ischaemic stroke is effective and safe within a 6 h window. MR CLEAN-LATE aimed to assess efficacy and safety of endovascular treatment for patients treated in the late window (6–24 h from symptom onset or last seen well) selected on the basis of the presence of collateral flow on CT angiography (CTA). Methods: MR CLEAN-LATE was a multicentre, open-label, blinded-endpoint, randomised, controlled, phase 3 trial done in 18 stroke intervention centres in the Netherlands. Patients aged 18 years or older with ischaemic stroke, presenting in the late window with an anterior circulation large-vessel occlusion and collateral flow on CTA, and a neurological deficit score of at least 2 on the National Institutes of Health Stroke Scale were included. Patients who were eligible for late-window endovascular treatment were treated according to national guidelines (based on clinical and perfusion imaging criteria derived from the DAWN and DEFUSE-3 trials) and excluded from MR CLEAN-LATE enrolment. Patients were randomly assigned (1:1) to receive endovascular treatment or no endovascular treatment (control), in addition to best medical treatment. Randomisation was web based, with block sizes ranging from eight to 20, and stratified by centre. The primary outcome was the modified Rankin Scale (mRS) score at 90 days after randomisation. Safety outcomes included all-cause mortality at 90 days after randomisation and symptomatic intracranial haemorrhage. All randomly assigned patients who provided deferred consent or died before consent could be obtained comprised the modified intention-to-treat population, in which the primary and safety outcomes were assessed. Analyses were adjusted for predefined confounders. Treatment effect was estimated with ordinal logistic regression and reported as an adjusted common odds ratio (OR) with a 95% CI. This trial was registered with the ISRCTN, ISRCTN19922220. Findings: Between Feb 2, 2018, and Jan 27, 2022, 535 patients were randomly assigned, and 502 (94%) patients provided deferred consent or died before consent was obtained (255 in the endovascular treatment group and 247 in the control group; 261 [52%] females). The median mRS score at 90 days was lower in the endovascular treatment group than in the control group (3 [IQR 2–5] vs 4 [2–6]), and we observed a shift towards better outcomes on the mRS for the endovascular treatment group (adjusted common OR 1·67 [95% CI 1·20–2·32]). All-cause mortality did not differ significantly between groups (62 [24%] of 255 patients vs 74 [30%] of 247 patients; adjusted OR 0·72 [95% CI 0·44–1·18]). Symptomatic intracranial haemorrhage occurred more often in the endovascular treatment group than in the control group (17 [7%] vs four [2%]; adjusted OR 4·59 [95% CI 1·49–14·10]). Interpretation: In this study, endovascular treatment was efficacious and safe for patients with ischaemic stroke caused by an anterior circulation large-vessel occlusion who presented 6–24 h from onset or last seen well, and who were selected on the basis of the presence of collateral flow on CTA. Selection of patients for endovascular treatment in the late window could be primarily based on the presence of collateral flow. Funding: Collaboration for New Treatments of Acute Stroke consortium, Dutch Heart Foundation, Stryker, Medtronic, Cerenovus, Top Sector Life Sciences &amp; Health, and the Netherlands Brain Foundation.</p