Predictors of Intracranial hemorrhage after mechanical thrombectomy in distal middle cerebral artery occlusion.

Background: Stroke remains a major global cause of death and disability, with ischemic strokes accounting for most cases. Mechanical thrombectomy (MT) is well established for large-vessel occlusions, yet its role in distal middle cerebral artery (MCA) occlusions is less clearly defined. Intracranial hemorrhage (ICH), particularly symptomatic ICH (sICH), is a serious complication that may worsen outcomes. This study aimed to identify predictors of hemorrhagic transformation following MT for distal MCA occlusions. Methods: Between January 2016 and December 2022, 246 patients with distal MCA occlusion underwent MT. Patients were classified into three groups: no hemorrhage (n = 128), asymptomatic hemorrhage (n = 77), and symptomatic hemorrhage (n = 41). Clinical, imaging, and procedural variables were analyzed using univariate and multivariate logistic regression to determine predictors of sICH. Results: On univariate analysis, older age, higher NIHSS, lower ASPECTS, elevated systolic blood pressure, multiple thrombectomy passes, and incomplete reperfusion were associated with hemorrhagic-transformation.Multivariate regression identified elevated systolic blood pressure (aOR = 1.017, 95% CI 1.001–1.034, p = 0.032) and number of thrombectomy passes (aOR = 1.71, 95% CI 1.34–2.17, p < 0.001) as independent predictors of sICH, while successful final reperfusion (mTICI 2c/3) showed a protective trend (p = 0.053). Conclusions: Symptomatic intracranial hemorrhage after distal MCA thrombectomy is independently associated with elevated systolic blood pressure and repeated thrombectomy attempts. These results reinforce the importance of achieving the first-pass effect and maintaining systolic blood pressure below 150 mmHg to optimize safety and improve outcomes.