Background There is no consensus on the optimal treatment of non-acute basilar artery occlusion (BAO), and endovascular recanalization still poses a therapeutic challenge for these patients. We report a multicenter clinical experience of endovascular recanalization for symptomatic non-acute BAO and propose an angiographic grouping to determine which patient subgroup most benefits from this treatment.

Methods Forty-two patients with non-acute BAO with progressive or recurrent vertebrobasilar ischemic symptoms who underwent endovascular recanalization were retrospectively analyzed from January 2015 to December 2019. These patients were classified into three subtypes based on their occlusion length and distal collateral reconstruction on angiograms. The rates of technical success, periprocedural complications and outcome, any stroke or death within 1 month, and follow-up data were examined.

Results The success rate of endovascular recanalization was 76.2% (32/42). The rate of periprocedural complications was 14.3% (6/42). In the three subgroups (types I–III) the success rates of endovascular recanalization were reduced (90.0%, 71.4% and 50%, respectively, p=0.023), while the overall rates of periprocedural complications were increased (5.0%, 14.3% and 37.5%, respectively, p=0.034). Type I lesions, with short-segment occlusions and good distal BA collateral reconstruction, showed favorable responses to endovascular recanalization. The median follow-up time was 1 year (IQR 11.0–19.5 months), with any stroke or death during follow-up at a rate of 7.9%.

Conclusion Endovascular recanalization can be safe and feasible for reasonably selected patients with non-acute BAO, especially type I lesions, and offers an alternative choice for those with progressive or recurrent vertebrobasilar ischemic symptoms despite aggressive medical therapy.