E-066 First U.S. experience with the R4Q distal access catheter for contact aspiration mechanical thrombectomy in emergent large vessel occlusion acute ischemic stroke

Abstract

Background Novel devices are being developed to maximize the efficacy of mechanical thrombectomy (MT). The MIVI R4Q series of distal access catheters has a unique design with an 0.20-inch wire (117 cm length) that replaces the proximal three quarters of the catheter and is attached to a distal catheter (25 cm length). The proximal end is flared with an outside diameter of 0.088 inch so that the outside is sealed with the inside of an 8F guide catheter allowing direct aspiration from the guide catheter thus providing greater aspiration force than smaller diameter catheters. This is the first report of patients in the United States using this technology to perform contact aspiration (CA). Methods We retrospectively reviewed all patients who underwent MT with the R4Q system at three high volume stroke centers. Baseline demographic and clinical data, as well as technical and clinical outcomes were recorded. Statistical comparison of rates of successful revascularization (SR) mTICI score 2b-3 and first pass effect (FPE) with MIVI technology were compared to the CA arms of ASTER and COMPASS using the Fischer’s Exact Test. Results 32 consecutive patients were identified. Median presenting NIHSS score at admission was 18. The site of occlusion was the middle cerebral artery M1 segment in 11 (34.4%), M2 segment in 6 (19%), M3 segment in 1 (3.1%), internal carotid artery in 8 (25%), tandem cervical ICA and intracranial occlusion in 2 (6.2%), ACA in 2 (6.3%), and basilar artery in 2 (6.3%). The R4Q was successfully delivered to the point of occlusion in 28 (87%) patients. SR to mTICI score 2b-3 on FPE was achieved in 21/32 (65%) patients and 16/26 (62%) patients where the R4Q was successfully delivered without a stent retriever. Final mTICI 2b-3 was achieved in 29/32 (91%) patients and 26/28 (93%) patients where the R4Q was successfully delivered. Three (9%) patients had intracranial hemorrhage – all HI1 (ECASS 2), 2 (6%) patients had vasospasm, and 1 (3%) patient had an embolus to a new territory. Fourteen patients (44%) had a 90-day modified Rankin scale (mRS) 0–2. SR with MIVI was similar to results from ASTER (91% vs. 85%, p=0.58) and COMPASS (91% vs 83%, p=0.41). FPE with MIVI was more frequent than in ASTER (62% vs. 26%, p=0.0009) and equivalent to COMPASS (62% vs 57%, p=0.83) and more frequent in comparison to the combined ASTER and COMPASS cohort (62% vs. 40%, p=0.04). Conclusion The R4Q family of catheters incorporates novel technology for CA. This series demonstrates a high FPE and similar rates of SR compared with published data using other aspiration catheters. Further prospective studies of this technology are planned to evaluate its clinical efficacy. Disclosures R. Torabi: None. M. Mokin: 1; C; NIH R21NS109575. 2; C; Medtronic, Canon Medical, Cerenovus. 4; C; Serenity Medical, Synchron, Endostream, VICIS. Z. Ren: None. A. Siddiqui: 1; C; NIH/NINDS, Cerenovus, Medtronic, Microvention, MUSC, Penumbra. 2; C; Amnis Therapeutics, Boston Scientific, Canon Medical Systems USA, Cerebrotech Medical Systems, Cerenovus, Corindus, Endostream Medical, Guidepoint Global Consulting, Imperative Care, Integra, Medtronic, Microvention, Minnetronix Neuro, Northwest University, Penumbra, Q’Apel Medical, Rapid Medical, Rebound Therapeutics, Serenity Medical, Silk Road Medical, StimMed, Stryker, Three Rivers Medical, VasSol, W.L. Gore & Associates. 4; C; Adona Medical, Amnis Therapeutics, BlinkTBI, Buffalo Technology Partners, Cardinal Consultants, Cerebrotech Medical Systems, Cognition Medical, Endostream Medical, Imperative Care, International Medical Distribution Partners, Neurovascular Diagnostics, Q’Apel Medical, Rebound Therapeutics, Rist Neurovascular, Sense Diagnostics, Serenity Medical, Silk Road Medical, Spinnaker Medical, StimMed Synchron, Three Rivers Medical, VasSol, W.L Gore & Associates. E. Levy: 2; C; Claret Medical, GLG Consulting, Guidepoint Global, Imperative Care, Medtronic, Rebound Therapeutics, StimMed. 4; C; NeXtGen Biologics, RAPID Medical, Claret Medical, Cognition Medical, Imperative Care, Rebound Therapeutics, StimMed, Three Rivers Medical. 6; C; National PI: Medtronic, Steering committees for SWIFT Prime and SWIFT Direct trials, Honorarium for Training and Lectures: Medtronic, Advisory Board: Styker (AIS clinical advisory board), NeXtGen Biologics, MEDX, Cognition Medical, Endostream Medical, Site PI: Microvention (Confidence Study). M. Waqas: None. A. Arthur: 1; C; Balt, Cerenovus, Medtronic, Microvention, Penumbra, Siemens, Stryker. 2; C; Johnson & Johnson, Microvention, Medtronic, Penumbra, Scientia, Siemens, Stryker. 4; C; Bendit, Cerebrotech, Endostream, Magneto, Marblehead, Neurogami, Serenity, Synchron, Triad Medical, Vascular Simulations. D. Hoit: 2; C; Medtronic, Microvention. 4; C; Silver Bullet, Cerebrotech, Marblehead Medical. C. Nickele: 1; C; Microvention. 2; C; Leica. V. Inoa: None. B. Jankowitz: 2; C; Stryker, Medtronic.