BackgroundExtensive clot burden in tandem strokes accounts for poor mechanical thrombectomy (MT) outcomes. Several studies have shown the benefit of balloon guide catheters (BGCs) in MT and carotid artery stenting.ObjectiveIn view of this potential benefit, to investigate the safety and effectiveness of proximal flow arrest using a BGC during concurrent MT and carotid revascularization for tandem stroke treatment in a comparative, propensity score-matched (PSM) study.MethodsPatients with a tandem stroke identified from our endovascular database were dichotomized into groups treated with BGCs versus conventional guide catheters. One-to-one PSM adjustment for baseline demographics and treatment selection bias using nearest-neighbor matching was performed. Patient demographics, presentation characteristics, and procedural details were recorded. Outcomes assessed were final modified Thrombolysis in Cerebral Infarction (mTICI) grade, periprocedural symptomatic intracranial hemorrhage (sICH) rate, in-hospital mortality, and 90-day modified Rankin Scale (mRS) score. Mann-Whitney U test and multivariate logistic regression were performed to compare procedural parameters and clinical outcomes.ResultsConcurrent carotid revascularization (stenting with/without angioplasty) and MT was performed in 125 cases (BGC: 85; no BGC: 40). After PSM (40 patients/group), the BGC group had a significantly shorter procedure duration (77.9 vs 61.5 min; OR=0.996; P=0.006), lower discharge National Institutes of Health Stroke Scale score (8.0 vs 11.0; OR=0.987; P=0.042), and higher odds of 90-day mRS 0–2 score (52.3% vs 27.5%; OR=0.34; P=0.040). On multivariate regression, the BGC group had a significantly higher first pass effect rate (mTICI 2b or 3)(OR=1.115, 95% CI 1.015 to 1.432; P=0.013) and lower periprocedural sICH rate (OR=0.615, 95% CI 0.406 to 0.932; P=0.025). No difference in in-hospital mortality was observed (OR=1.591, 95% CI 0.976 to 2.593; P=0.067).ConclusionBGCs used for concurrent MT–carotid revascularization with flow arrest were safe and resulted in superior clinical and angiographic outcomes in patients with a tandem stroke.