Evolution of Intra-arterial Therapy for Acute Ischemic Stroke in The Netherlands: MR CLEAN Pretrial Experience

Introduction: The Multicenter Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands (MR CLEAN) trial showed efficacy of intra-arterial (IA) treatment in acute ischemic stroke (AIS). We studied the evolution of IA treatment for AIS and its effects on clinical outcome and recanalization in The Netherlands in the pre-MR CLEAN era. Methods: Data on 517 patients with AIS treated with IA therapy were collected retrospectively from all intervention centers in The Netherlands from 2002 to the start of participation in the MR CLEAN trial. Clinical outcome was measured by means of the modified Rankin Scale score and recanalization with the Thrombolysis in Cerebral Infarction Scale. Results: IA therapy was first used in patients with basilar artery occlusion. Over the years, there was a gradual increase in the number of anterior circulation strokes treated. There was a shift in applied therapies from primary IA therapy to combined intravenous and IA therapy and from IA thrombolysis to mechanical thrombectomy. Time from symptom onset to treatment decreased. Recanalization rates gradually increased. At the same time, there was a trend toward more favorable outcomes after 3 months and fewer deceased patients both at discharge and after 3 months. However, none of these changes reached statistical significance. Conclusion: The treatment approach used in the MR CLEAN trial was the result of an evolution of practise in the preceding years, with gradual improvement in technical and clinical outcomes.