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

Abstract 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.