Background: Endovascular therapy (EVT) has markedly improved outcomes in large vessel occlusion stroke. However, early neurological deterioration (END) remains a critical challenge, often driven by re-occlusion, hyperperfusion, or hemorrhagic transformation (HT). This study evaluated the role of early transcranial Doppler (TCD) monitoring after EVT and its association with patient outcomes. Methods: In this IRB-approved multicenter study (2019-2025), we included patients with middle cerebral artery (MCA) M1 or M2 occlusions who underwent successful EVT (TICI Score ≥2b) within 24 hours of onset and received TCD with concurrent blood pressure monitoring within 8-12 hours post-EVT. Mean flow velocity (MFV) and pulsatility index (PI) were measured bilaterally in the M1 and M2 segments. Ratios of MFV and PI were calculated using the occluded MCA compared to the contralateral side. Multivariate logistic regression assessed the association of MFV and PI ratios with HT and 3-month modified Rankin Scale (mRS). Analyses were adjusted for age, sex, baseline NIHSS, and post-EVT MAP in a subset of models. Results: A total of 70 patients (41 male; mean age 69.9±6.7 years) met inclusion criteria for the study. HT (confirmed on SWAN by neuro-radiologist) occurred in 45 (64.3%) patients. At 3 months, 25 (35.7%) experienced poor functional outcomes (mRS≥3). In adjusted analyses for age, sex, and baseline NIHSS, lower M2 PI ratio and higher M1 and M2 MFV ratios were significantly associated with HT (OR=3.306, P<0.001; OR=1.871, P=0.011; OR=11.011, P=0.008) and poor 3-month mRS (OR=4.408, P<0.001; OR=2.874, P<0.001; OR=1.755, P=0.006). After further adjustment for post-EVT MAP, lower M2 PI ratio remained independently associated with increased odds of both HT (OR=2.623, P=0.008) and poor functional outcome (OR=3.247, P=0.004). Conclusion: Early TCD after EVT predicts HT and poor outcomes, with lower M2 PI ratios emerging as a key marker of hyperperfusion-related injury. These findings highlight the utility of TCD as a noninvasive tool for early risk stratification and individualized post-EVT management. Larger, prospective studies are needed to validate these results and establish standardized TCD-based monitoring protocols in clinical practice. Funding support: The project described was partially supported by the NIH, Grant UL1TR001442. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.
Phan et al. (Thu,) studied this question.