Synchronous Superficial Middle Cerebral Vein Outflow Correlates Favorable Tissue Fate after Mechanical Thrombectomy for Acute Ischemic Stroke.

Rationale and Objectives: The purpose of this study was to determine the association between hemispheric synchrony in venous outflow at baseline and tissue fate after mechanical thrombectomy (MT) for acute ischemic stroke (AIS). Materials and Methods: A two-center retrospective analysis involving AIS patients who underwent MT was performed. The four cortical veins of interest include the superficial middle cerebral vein (SMCV), sphenoparietal sinus (SS), vein of Labb & eacute; (VOL), and vein of Trolard (VOT). Baseline computed tomography perfusion data were used to compare the following outflow parameters between the hemispheres: first filling time ( triangle FFT), time to peak ( triangle TTP) and total filling time ( triangle TFT). Synchronous venous outflow was defined as triangle FFT = 0. Multivariable regression analyses were performed to evaluate the association of venous outflow synchrony with penumbral salvage, infarct growth, and intracranial hemorrhage (ICH) after MT. Results: A total of 151 patients (71.4 +/- 13.2 years, 65.6% women) were evaluated. Patients with synchronous SMCV outflow demonstrated significantly greater penumbral salvage (41.3 mL vs. 33.1 mL, P = 0.005) and lower infarct growth (9.0 mL vs. 14.4 mL, P = 0.015) compared to those with delayed SMCV outflow. Higher triangle FFT SMCV ( beta = -1.44, P = 0.013) and triangle TTP SMCV ( beta = -0.996, P = 0.003) significantly associated with lower penumbral salvage, while higher triangle FFT SMCV significantly associated with larger infarct growth ( beta = 1.09, P = 0.005) and increased risk of ICH (odds ratio [OR] = 1.519, P = 0.047). Conclusion: Synchronous SMCV outflow is an independent predictor of favorable tissue outcome and low ICH risk, and thereby carries the potential as an auxiliary radiological marker aiding the treatment planning of AIS patients.