Endovascular recanalization for symptomatic non-acute middle cerebral artery occlusion: proposal of a new angiographic classification

Background Endovascular recanalization for medically refractory non-acute middle cerebral artery (MCA) occlusion remains a clinical dilemma, and limited data are available. We report the multicenter clinical results of endovascular recanalization for symptomatic non-acute MCA occlusion and propose a new angiographic classification to explore which subgroups of patients are most suitable for this treatment. Methods From January 2015 to December 2019, 50 consecutive patients who underwent endovascular recanalization for recurrent symptomatic non-acute MCA occlusion were analyzed retrospectively. All patients were divided into three types according to the angiographic classification. The technical success rate, periprocedural complications, rate of stroke or death within 30 days, and follow-up results were evaluated. Results The overall technical success rate was 84.0% (42/50). The perioperative complication rate was 14.0% (7/50), and the rate of stroke or death within 30 days was 12.0% (6/50). The revascularization success rate was higher in patients with type I occlusion than in those with type II or type III occlusion (95.5%, 83.3%, and 60%, respectively; p=0.014), and the opposite was true for the perioperative complication rate (4.5%, 11.1%, and 40.0%, respectively; p=0.013). The median clinical follow-up period was 13.4 months (IQR 12.5–15.6), and the rate of stroke or death beyond 30 days was 8.3%. Conclusions Endovascular recanalization for non-acute MCA occlusion is technically feasible in reasonably selected patients, especially type I patients, and has potential as an alternative option for patients with recurrent stroke or transient ischemic attack in the short term despite optimal medical therapy.