Objective To explore the incidence,influencing factors,and prognosis of stroke-associated pneumonia(SAP)in patients with acute vertebrobasilar artery occlusion(VBAO)after endovascular treatment.Methods Clinical and imaging data of 577 patients diagnosed with acute VBAO and scheduled to undergo endovascular treatment within 24 hours of occlusion from December 2015 to December 2018 at 21 stroke centers in China were retrospectively collected.Patients were divided into the SAP group(368 cases)and the non-SAP group(209 cases)based on the occurrence of SAP.A comparison was made between the two groups regarding stroke-related medical history,stroke subtype,National Institutes of Health Stroke Scale(NIHSS)score,Glasgow Coma Scale(GCS)score,Alberta Stroke Program Early CT Score,intracranial vascular collateral circulation grading,anesthesia method,time from occlusion to puncture,puncture to reperfusion time,successful reperfusion,and symptomatic intracranial hemorrhage.Factors related to SAP were analyzed,and the impact on clinical prognosis was further analyzed based on 90-day follow-up data.Normally distributed continuous variables were expressed as (xˉ)±s and analyzed using independent sample t-test,while non-normally distributed continuous variables were expressed as M(Q1,Q3)and analyzed using Mann-Whitney U test.Categorical data were presented as number(%)and analyzed using χ2 test.Parameters with P<0.1 in univariate analysis were included in the multivariate logistic regression analysis with SAP as the dependent variable.Results Compared with the non-SAP group,the SAP group had higher NIHSS scores,lower GCS scores,worse intracranial vascular collateral circulation,a higher proportion of general anesthesia,and longer puncture to reperfusion time,with statistically significant differences(all P<0.05);other baseline characteristics showed no statistically significant differences between the two groups(all P>0.05).Multivariate logistic regression analysis revealed that lower GCS score(OR:0.908,95%CI:0.860 to 0.960,P=0.001),general anesthesia(OR:2.507,95%CI:1.519 to 4.138,P<0.001),and longer puncture to reperfusion time(OR:1.003,95%CI:1.000 to 1.006,P=0.033)were independent risk factors for SAP.Prognostic analysis showed a significant negative correlation between SAP and good prognosis at 90 days(OR:0.605,95%CI:0.386 to 0.948,P=0.028).Conclusion Lower GCS score,general anesthesia and longer puncture to reperfusion time are independent risk factors for SAP in patients undergoing endovascular treatment for VBAO.Patients with SAP have a poorer prognosis.