Introduction Endovascular thrombectomy (EVT) for acute ischemic stroke is the current standard of care. Previous investigations explored the impact of EVT total procedure time (PT) on clinical outcomes. Longer procedures correlated with worse outcomes. The underlying mechanisms explaining why minutes of PT have a more pronounced effect on outcomes than onset to puncture time remain unexplored. We hypothesized that the duration of aspiration catheters indwelling in the intracranial vasculature contributes to a further reduction in blood flow to the ischemic penumbra, thereby diminishing the efficacy of EVT.

Methods We employ a combination of an in-vitro flow model and data from an international multicenter registry. Using a flow model of EVT, we tested the impact of placing different size endovascular catheter on the cerebral blood flow in the middle cerebral artery (MCA) and anterior cerebral (ACA) using 5 independent simulations. We then used a large multicenter retrospective cohort of patients to study the impact of time from catheter placement in the intracranial vasculature to revascularization (icPT) on EVT outcomes. Primary outcome included 90-day functional independence defined as modified Rankin Score (mRS) 0–2.

Results Using an in-vitro flow model of cerebral vasculature, we first demonstrate that 6–8F catheters resulted in a size-dependent reduction of ipsilateral cerebral blood flow in the MCA (50%) and ACA (70%). Using a prospective registry-based study from 30 comprehensive stroke centers, we included 3318 EVT patients with recorded icPT. Using regression models controlling for covariates, icPT predicted lower rates of 90-day functional independence (aOR=0.87, p<0.01), higher odds of 90-day mortality (aOR=1.03, p<0.01), higher odds of decompressive craniectomy (aOR=1.07, p<0.01), and higher odds of post-procedural sICH (aOR=1.07,p<0.01). Every 10 min increase in icPT is associated with 13% lower odds of 90-day functional independence. The impact of icPT on outcomes was independent of successful recanalization but was potentiated by the use of larger bore catheters. In cases of complete internal carotid artery occlusion, large catheter placement did not impact outcomes. Techniques requiring distal placement of large catheters (contact aspiration) led to higher impact of icPT on outcomes compared to techniques not requiring distal catheter placement (stent retriever). Reduction in blood pressure (BP) intra-procedure amplifies the effect of icPT on outcomes. To identify the optimal cut-off if icPT for propensity score (PS) matching, we used the Youden’s index applied to the receiver operating characteristic. A cut-off at 30 min of icPT was deemed optimal. We performed PS-matched analysis of patients with successful recanalization that was achieved in <30 min versus ≥30 min of icPT. Comparing the two groups (N=1006/group), patients with icPT <30 min had better post-procedural NIHSS and more pronounced improvement in NIHSS between admission and post-procedure compared to those with ≥30 min (p<0.001). On logistic regression, icPT < 30 min was associated with 1.62 higher odds of good functional outcome at 90 days (p<0.001).

Conclusions This study demonstrates the risks associated with duration of catheter use during EVT, and propose strategies to mitigate these risks including BP augmentation and limiting the duration of distal catheter placement in longer procedures.

Disclosures A. Alawieh: 6; C; Penumbra. S. Elawady: None. R. Chalhoub: None. C. Cunningham: None. Y. Zohdy: None. B. Howard: None. C. Cawley: None. D. Barrow: None. F. Akbik: None. A. Pabaney: None. F. Tong: None. S. Alkasab: 1; C; Stryker. P. Jabbour: 2; C; Balt, Cerus endovascular, MicroVention, Medtronic. N. Goyal: None. A. Arthur: 1; C; Balt, Medtronic, Microvention, Penumbra, Siemens. 2; C; Arsenal, Balt, Johnson and Johnson, Medtronic, Microvention, Penumbra, Scientia, Siemens, Stryker. 4; C; Azimuth, Bendit, Cerebrotech, Endostream, Magneto, Mentice, Neurogami, Neuros, Scientia, Serenity, Synchron, Tulavi, Vastrax, VizAI. F. Siddiqui: None. S. Yoshimura: None. M. Park: 5; C; Medtronic. W. Brinjikji: None. C. Matouk: 2; C; Silk Road, Penumbra, Microvention, Stryker. 3; C; Silk Road, Penumbra. D. Romano: None. D. Altschul: None. R. Williamson: None. M. Moss: None. R. De Leacy: 1; C; Hyprevention, Kaneka Medical, Siemens Healthineers, SNIS foundation. 2; C; Stryker Neurovascular, Imperative Care, Cerenovus, Asahi Intec. 4; C; Synchron, Endostream, Q’Apel, Spartan Micro. 6; C; Editorial Board JNIS. M. Ezzeldin: None. P. Kan: 1; C; U18EB029353–01. 2; C; Stryker Neurovascular, Imperative Care, Microvention. 6; C; Editorial Board JNIS. M. Levitt: 1; C; Stryker, Medtronic. 2; C; Medtronic, Aeaean Advisers. 4; C; Hyperion Surgical, Proprio, Synchron, Cerebrotech, Fluid Biomed, Stereotaxis. 6; C; Travel support: Penumbra, Editorial board, Journal of NeuroInterventional Surgery, Metis Innovative: Adviser. R. Grandhi: None. J. Mascitelli: 2; C; Stryker. J. Grossberg: 1; C; Georgia Research Alliance, Emory Medical Care Foundation, Department of Defense, Neurosurgery Catalyst. 4; C; NTI, Cognition. A. Spiotta: 2; C; Stryker, Terumo, Penumbra, RapidAI.