Prognostic Impact of Collateral Circulation in Direct Thrombectomy versus Bridging Thrombectomy for Acute Ischemic Stroke Patients with Anterior Circulation Large Vessel Occlusion: A Retrospective Comparative Study

Zuopeng Li¹Chao Cai²Yuan Qin^3*

• ¹The First Hospital of Shanxi Medical University, Taiyuan, China
• ²The First Clinical Medical College of Shanxi Medical University, Taiyuan, China
• ³the People's Hospital of Pianguan County, Pianguan, China

Objective: To evaluate the prognostic impact of collateral circulation on outcomes of direct thrombectomy (DT) versus bridging thrombectomy (BT) for acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion (LVO). Method: This retrospective study included 460 AIS patients with anterior circulation LVO who underwent either DT (n = 220) or BT (n = 240). Collateral status was assessed using multiphase computed tomographic angiography. The primary outcome was functional prognosis at 3 months, measured by the modified Rankin Scale (mRS). Prognostic factors for good prognosis (90-day mRS ≤2) and adverse events were identified through multivariate logistic regression and receiver operating characteristic (ROC) analyses. Results: The BT group had significantly higher rates of intracerebral hemorrhage and hemorrhagic transformation compared to the DT group (p < 0.05). Good collateral circulation was independently associated with good prognosis and lower risk of serious adverse events (p < 0.001). Lower NIHSS scores, shorter OTR, absence of atrial fibrillation, and lower serum BNP levels were also significantly associated with favorable outcomes in AIS patients (all p < 0.01). Elevated serum BNP levels increased the risk of serious adverse events in both DT and BT groups (p < 0.001). ROC analysis showed that a combined model including NIHSS, BNP, collateral circulation, onset-to-reperfusion time, and atrial fibrillation achieved high predictive performance for good prognosis (AUC = 0.907, 95% CI: 0.881–0.934, p < 0.001). Conclusion: Collateral circulation is a strong predictor of both functional recovery and risk of adverse events in AIS patients undergoing thrombectomy, regardless of treatment strategy. While serum BNP may offer additional prognostic value, its moderate performance and overlap with cardiovascular conditions suggest that it should be interpreted cautiously. Pre-intervention collateral assessment remains a valuable tool for guiding individualized treatment decisions.