Endovascular management of tandem occlusions: current evidence and future directions

Tandem occlusions (TOs)-concurrent extracranial large artery steno-occlusion and intracranial artery occlusion-represent a challenging clinical predicament. Stroke due to TOs is associated with high mortality and morbidity. Because of increased clot burden compared with single occlusions and impaired anterograde flow, intravenous thrombolysis may be less effective, and outcomes are poor without timely intervention. Endovascular thrombectomy (EVT) has become the cornerstone of intracranial revascularization, but the optimal management of the extracranial carotid lesion remains undefined. Evidence from observational studies and early-phase randomized controlled trials (RCTs) is mixed. Currently, no standardized treatment approach is widely accepted, and practice patterns are guided by personal preference and expert opinion. Ongoing RCTs seek to determine whether there is an optimal approach to EVT in the setting of TO with respect to (a) technique and (b) the order of treatment. Even on completion of active RCTs, a dearth of evidence will remain on the optimal antithrombotic therapy, exact device selection, and EVT in dissection-associated TOs and posterior circulation TOs. In the present narrative review, we critically appraise the literature on the endovascular management of TOs and offer considerations for practice that may help to reduce the burden of tandem occlusion strokes.