Robert W. Regenhardt, MD, PhD
The revolution of acute stroke care, with the 2015 trials demonstrating superiority of endovascular thrombectomy (ET) compared to tPA alone and the subsequent DAWN and DEFUSE 3 trials extending its time window, has raised many questions about which patients will experience net benefit from this powerful therapy. Certainly, some vessel occlusions are more amenable to ET than others, but should the presence of technically difficult occlusions, with perhaps higher procedural risks, limit eligibility? Though poorly represented, patients with anterior circulation tandem lesions, involving both the cervical internal carotid artery (ICA) and an intracranial artery, experienced similar benefits as those with isolated intracranial occlusions in the HERMES meta-analysis. It is unclear if the etiology of tandem lesions predicts outcomes, if etiology should influence the decision to undergo ET, or if it should influence the procedural approach.
The two most common etiologies of tandem lesions are carotid atherosclerosis and carotid dissection. Treatment typically occurs in two phases: management of the cervical ICA lesion by stenting, angioplasty, both, or medical treatment alone, and management of the intracranial occluded vessel by stent retriever or direct aspiration first pass technique. The order of these phases remains controversial, with some centers starting with the intracranial lesion as stent retrievers only require a small microcatheter for deployment. Stenting versus angioplasty of the cervical ICA can be debated based on adequacy of collaterals, risk of reperfusion injury, risk of immediate dual antiplatelet therapy, and other individualized factors.