To investigate the interaction between intravenous thrombolysis (IVT) and transfer strategies (mothership vs. transfer) on outcomes following endovascular thrombectomy (EVT) for vertebrobasilar artery occlusions (VBAOs).

EVT has become a standard intervention for acute ischemic stroke caused by VBAOs.

A retrospective analysis was conducted on VBAO patients who underwent EVT. Patients were categorized based on treatment type: IVT followed by EVT or EVT alone. Transfer strategies were classified as mothership or transfer. The primary outcomes were modified Rankin Scale (mRS≤3) and mortality at 90 days.

Among 175 patients, the median age was 67 years with 54.9% males. Among these, 33 patients (18.9%) received IVT before EVT, while 142 (81.1%) underwent EVT alone. Among all patients, 48 (27.4%) presented as mothership, and 127 (72.6%) were transfers. In bridging IVT cohort, mRS≤ 3 at 90 days was observed in 58.3% of the mothership group, a higher rate compared to 38.9% in the transfer group. For EVT alone cohort, the mothership group demonstrated a lower rate of mRS≤ 3 at 90 days (35.3%) compared to transfer (45.8%). The mothership group in the IVT cohort had a 90-day mortality rate of 41.7% compared to 50.0% in the transfer group, while for patients undergoing EVT alone, the mothership group had a mortality rate of 52.9% versus 43.8% in the transfer group. Interaction analysis indicated that the mothership strategy may have more pronounced benefits for IVT-refractory patients; however, the overall interaction effect was not statistically significant (p>0.05).

In patients with VBAOs undergoing EVT, bridging IVT showed better clinical outcomes in the mothership group compared to those transferred from outside hospitals, particularly in contrast to the EVT-alone group. These findings suggest that the mothership strategy may benefit patients who are potentially IVT-refractory. Further studies with larger sample sizes are needed to confirm these results.