Background and purpose: Data on procedure time (PT) for mechanical thrombectomy (MT) are scarce. Moreover, the relationship among PT, postprocedural hemorrhagic transformation (HT), and functional outcomes in MT patients remains unclear. We investigated whether postprocedural HT mediated the relationship between PT and functional outcomes in patients with stent-retriever thrombectomy.
Methods: We retrospectively analyzed consecutive patients who underwent MT at two comprehensive stroke centers. PT was defined as the time from puncture to first successful recanalization or to abortion of the procedure if successful recanalization was not achieved. A favorable outcome was defined as a 90-day modified Rankin Scale score of 0-2. HT was classified using the European Cooperative Acute Stroke Study definition.
Results: Among 283 patients (mean age, 67.2 ± 11.9 years; male, 53.7%), 124 (43.8%) patients had a favorable outcome and 27 (9.5%) patients experienced symptomatic intracranial hemorrhage (sICH). Whether in the overall cohort or in the successful recanalization cohort, extended PT was an independent predictor for a poor outcome (per 30 min: OR 1.433, 95% CI 1.062-1.865, p = 0.019; OR 1.522, 95% CI 1.062-2.159, p = 0.020, respectively) and sICH (per 30 min: OR 1.391, 95% CI 1.030-1.865, p = 0.029; OR 1.716, 95% CI 1.161-2.648, p = 0.009, respectively). Moreover, postprocedural HT might partially explain the worse function outcomes in patients with an extended PT (the regression coefficient was changed by 28.2% and 28.1%, respectively).
Conclusions: The PT is an independent predictor for 90-day outcomes in stent-retriever thrombectomy patients. Postprocedural HT was partially responsible for the worse outcome in patients who experienced a longer PT.
Keywords: Hemorrhagic transformation; Mechanical thrombectomy; Outcome; Stroke.