Association between Cerebral Blood Volume Index and Excellent Reperfusion in Acute Ischemic Stroke Patients Undergoing Mechanical Thrombectomy.

Introduction: Excellent reperfusion following mechanical thrombectomy (MT) is strongly associated with favorable clinical outcomes in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). This study aims to investigate the association between the cerebral blood volume (CBV) index-a surrogate marker of collateral status-and the likelihood of achieving excellent reperfusion after MT in AIS-LVO patients.

Methods: A retrospective analysis was conducted on a consecutive series of anterior circulation AIS-LVO patients undergoing MT. CBV index was calculated using RAPID software as the ratio of mean CBV in the penumbral region (Tmax > 6 seconds) to that in the unaffected brain region (Tmax≤4 seconds). The primary outcome was excellent reperfusion, defined as an expanded Thrombolysis in Cerebral Infarction (eTICI) score of 2c/3.

Results: Of the 245 patients (54.70% male, median age 71 years), 152 (62.04%) achieved excellent reperfusion. ROC analysis identified a CBV index ≥0.6 as the optimal cutoff for predicting excellent reperfusion (AUC=0.743). Multivariable logistic regression showed a positive association between the CBV index and excellent reperfusion (adjusted OR = 1.221 per 0.1-point increase, 95% CI: 1.028-1.449, p=0.023). Patients with a favorable CBV index (≥0.6) were significantly more likely to achieve excellent reperfusion (adjusted OR = 2.785, 95% CI: 1.258-6.164, p = 0.012).

Discussion: These findings suggest that the CBV index is an independent predictor of excellent reperfusion after MT in AIS-LVO patients. This association may reflect the importance of tissue- level collateral perfusion in achieving successful reperfusion. Limitations include the singlecenter, retrospective design and the potential for selection bias.

Conclusion: The CBV index is positively associated with excellent reperfusion in AIS-LVO patients undergoing MT. Further prospective studies are warranted to validate these findings and explore the underlying mechanisms.