Aiming for TICI 4: angiographic and ultrasonographic predictors of parenchymal hemorrhage after successful thrombectomy

Background Hemorrhagic transformation after thrombectomy is associated with poor outcomes. This study aimed to assess post-thrombectomy angiographic signs and increased blood flow on transcranial Doppler as potential predictive factors for parenchymal hemorrhage after successful endovascular stroke treatment. Methods This cohort study included consecutive patients who underwent endovascular stroke treatment at a comprehensive stroke center with successful recanalization and 24-hour follow-up imaging available. Angiographic post-thrombectomy signs, including the blush sign, early venous filling, and punctate dilations, were retrospectively and blindly assessed. The mean blood flow velocity ratio of the recanalized artery was collected and compared with the contralateral artery, defining hyperperfusion as a ratio greater than 1.3. Control 24-hour CT scans were reviewed, and hemorrhagic transformation was classified. Unadjusted and clinical variable-adjusted logistic regression analyses were performed. Results A total of 362 patients were included in the analysis, with 28 (7.7%) presenting with parenchymal hemorrhage. The blush sign (adjusted OR 3.6, 95% CI 1.3 to 9.4, P=0.01), early venous filling (adjusted OR 6.1, 95% CI 1.9 to 20.0, P=0.003), a combination of both signs (adjusted OR 7.9, 95% CI 2.0 to 30.8, P=0.003), and Doppler-assessed hyperperfusion (adjusted OR 5.9, 95% CI 1.1 to 31.5, P=0.038) were independent predictors of parenchymal hemorrhage. A model incorporating these three variables presented an area under the curve of 0.82 (95% CI 0.67 to 0.99, P<0.001), indicating excellent predictive accuracy for identifying parenchymal hemorrhage following successful thrombectomy. Conclusion Angiography and transcranial Doppler ultrasonography may provide early signs that accurately predict parenchymal hemorrhage following successful recanalization.