Downstream Occlusion During Mechanical Thrombectomy: Clinical Implications and Endovascular Trajectory

Area of Science:

• Neurology
• Interventional Neuroradiology
• Vascular Surgery

Background:

• Downstream occlusion (DOC) is a frequent complication during mechanical thrombectomy (MT) for acute large vessel occlusion (LVO).
• The prevalence, predictors, and clinical impact of DOC remain incompletely understood.
• Understanding DOC is crucial for optimizing MT procedures and patient outcomes.

Purpose of the Study:

• To determine the prevalence and independent predictors of DOC in patients undergoing MT for intracranial LVO.
• To analyze the endovascular trajectory and clinical outcomes of patients with and without DOC.
• To evaluate the effectiveness of subsequent recanalization attempts in managing DOC.

Main Methods:

• Retrospective analysis of 703 patients undergoing MT for acute intracranial LVO (2010-2021).
• Angiographic identification of DOC as a new occlusion distal to the primary site post-recanalization.
• Multivariate logistic regression for predictor analysis; comparison of outcomes between DOC and non-DOC groups.

Main Results:

• DOC occurred in 36.1% of patients, with atrial fibrillation and proximal occlusion as independent predictors.
• Patients with DOC showed comparable final successful recanalization (92.5%) and functional independence (40.2%) rates.
• Additional endovascular treatment for DOC improved reperfusion in 76.7% of cases, with variable functional benefit based on location.

Conclusions:

• DOC, despite procedural complexity, does not significantly impair final recanalization or functional outcomes.
• Effective management of DOC is achievable with further endovascular intervention.
• Attaining sufficient final reperfusion remains paramount in MT, even in the presence of DOC.