OBJECTIVE Tandem occlusions continue to represent a major challenge in patients with acute ischemic stroke (AIS). The anterograde approach with proximal to distal revascularization as well as the retrograde approach with distal to proximal revascularization have been reported without clear consensus or standard guidelines. METHODS The authors performed a comprehensive search of the PubMed database for studies including patients with carotid occlusions and tandem distal occlusions treated with endovascular therapy. They reviewed the type of approach employed for endovascular intervention and clinical outcomes reported with emphasis on the revascularization technique. They also present an illustrative case of AIS and concurrent proximal cervical carotid occlusion and distal middle cerebral artery occlusion from their own experience in order to outline the management dilemma for similar cases. RESULTS A total of 22 studies were identified, with a total of 790 patients with tandem occlusions in AIS. Eleven studies used the anterograde approach, 3 studies used the retrograde approach, 4 studies used both, and in 4 studies the approach was not specified. In the studies that reported Thrombolysis in Cerebral Infarction (TICI) grades, an average of 79% of patients with tandem occlusions were reported to have an outcome of TICI 2b or better. One study found good clinical outcome in 52.5% of the thrombectomy-first group versus 33.3% in the stent-first group, as measured by the modified Rankin Scale (mRS). No study evaluated the difference in time to reperfusion for the anterograde and retrograde approach and its association with clinical outcome. The patient in the illustrative case had AIS and tandem occlusion of the internal carotid and middle cerebral arteries and underwent distal revascularization using a Solitaire stent retrieval device followed by angioplasty and stent treatment of the proximal cervical carotid occlusion. The revascularization was graded as TICI 2b; the postintervention National Institutes of Health Stroke Scale (NIHSS) score was 17, and the discharge NIHSS score was 7. The admitting, postoperative, and 30-day mRS scores were 5, 1, and 1, respectively. CONCLUSIONS In stroke patients with tandem occlusions, distal to proximal revascularization represents a reasonable treatment approach and may offer the advantage of decreased time to reperfusion, which is associated with better functional outcome. Further studies are warranted to determine the best techniques in endovascular therapy to use in this subset of patients in order to improve clinical outcome.
Keywords: ACA = anterior cerebral artery; AIS = acute ischemic stroke; AP = anteroposterior; CCA = common carotid artery; CTA = CT angiography; DSA = digital subtraction angiography; ICA = internal carotid artery; IV = intravenous; MCA = middle cerebral artery; NIHSS = National Institutes of Health Stroke Scale; TICI = Thrombolysis in Cerebral Infarction; endovascular therapy; ischemic stroke; mRS = modified Rankin Scale; revascularization; tPA = tissue plasminogen activator; tandem occlusion.