Time Is Flow: The Impact of Intracranial Catheter Duration on Stroke Thrombectomy Outcomes

Introduction: Mechanical thrombectomy (MT) is the standard treatment for acute ischemic stroke (AIS). Despite procedural efficacy, longer procedure times have been linked to poorer outcomes. We investigated how prolonged intracranial catheter dwell time (icPT) impacts MT outcomes, hypothesizing that large-bore catheters reduce cerebral blood flow, worsening ischemic penumbra stress.

Methods: We conducted an in-silico flow model experiment to assess the impact of various catheter sizes on cerebral blood flow. Additionally, we conducted a registry-based study of patients undergoing MT for AIS from 30 centers internationally. IcPT was defined as the time from intracranial catheter placement to thrombectomy completion. Patients were stratified by icPT ( < 30 vs. ≥30 minutes), with propensity score matching (PSM) used to balance covariates. The primary outcome was the 90-day modified Rankin Score (mRS), with favorable outcomes defined as mRS 0-2. Secondary outcomes included 90-day mortality, symptomatic intracranial hemorrhage (sICH), and need for decompressive craniectomy.

Results: Using an in-vitro model, 6-8F catheters resulted in a size-dependent reduction of ipsilateral cerebral blood flow in the MCA and ACA (p < 0.01). Among 3318 EVT patients, icPT predicted lower rates of favorable outcome (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 sICH (aOR=1.07, p< 0.01). Every 10 min increase in icPT was associated with 13% lower odds of favorable outcome. The impact of icPT on outcome measures was maintained even in single pass MT and in patients without successful recanalization (P < 0.05). The impact of icPT was potentiated with using larger bore catheters (p < 0.01), and lower intraprocedural mean arterial pressure (p < 0.01).

Conclusion : Prolonged icPT during MT significantly reduces the likelihood of favorable outcomes, even when successful recanalization is achieved. Our findings emphasize the need for minimizing icPT and identify mitigation measures for longer procedures including augmenting blood-pressure and temporary catheter withdrawal.