Impact of Procedure Time on Outcomes of Thrombectomy for Stroke

Abstract

Background: Endovascular thrombectomy (ET) for acute ischemic stroke is the current standard of care. Although successful ET has high efficacy in improving functional outcomes, the decision to abort a long procedure remains a challenge. Longer procedure time (PT) has been associated with lower rates of functional independence.

Objectives: The objective of this study was to evaluate the impact of PT on outcomes and complications after ET using different techniques at a multicenter level and to define the risk of procedure extension in different patient cohorts.

Methods: Patients undergoing ET with a stent retriever (SR) or a direct aspiration at first pass technique at 7 U.S. centers between June 2013 and February 2018 were reviewed from prospectively maintained databases that include baseline variables and technical and clinical outcomes. Multivariate analyses were used to assess impact of PT on 90-day modified Rankin scores, successful recanalization, post-procedural symptomatic hemorrhage (sICH), and complications.

Results: The study included 1,359 patients and demonstrated a decreased likelihood of good functional outcomes (modified Rankin score 0 to 2) when PT extended beyond 30 min (p < 0.01). Rates of sICH and complications increased exponentially with PT (doubling rates of 26 and 50 min, respectively). The cumulative rate of successful recanalization and good outcomes plateaued after 60 min of PT. In patients with PT >30 min, fewer attempts predicted the success of ET and good outcomes (p < 0.01). Successful recanalization was achieved faster with the direct aspiration at first pass technique than in SR. The direct aspiration technique was more sensitive to PT than SR, and posterior stroke was more sensitive to PT than anterior stroke.

Conclusions: Longer ET procedures lead to lower rates of functional independence and higher rates of sICH and complications. Exceeding 60 min or 3 attempts should trigger careful assessment of futility and risks of continuing the procedure.

Keywords: aspiration thrombectomy; procedure time; stent retriever; stroke; thrombectomy.