Approximately 20-30% of patients with acute ischemic stroke, caused by large intracranial vessel occlusion, have a tandem lesion, defined as simultaneous presence of high-grade stenosis or occlusion of the cervical internal carotid artery and thromboembolic occlusion of the intracranial terminal internal carotid artery or its branches, usually the middle cerebral artery. Patients with tandem lesions have usually worse outcomes than patients with single intracranial occlusions, and intravenous thrombolysis is less effective in these patients. Although endovascular thrombectomy is currently a cornerstone therapy in the management of acute ischemic stroke due to large vessel occlusion, the optimal management of extracranial carotid lesions in tandem occlusion remains controversial. Acute placement of a stent in the cervical carotid artery lesion is the most used therapeutic strategy compared with stented balloon angioplasty and thrombectomy alone without carotid artery revascularization; however, treatment strategies in these patients are often more complex than with single occlusion, so treatment decisions can change based on clinical and technical considerations. The aim of this review is to analyze the results of different studies and trials, investigating the periprocedural neurointerventional management of patients with tandem lesions and the safety, efficacy of the different technical strategies available as well as their impact on the clinical outcome in these patients, to strengthen current recommendations and thus optimize patient care.

Endovascular thrombectomy is the standard treatment in selected patients with acute ischemic stroke and large vessel occlusion, but continuous improvement in angiographic and clinical outcome is still needed. Intra-arterial thrombolysis has been tested as a possible rescue tool in unsuccessful thrombectomy, or as an adjuvant therapy after the endovascular procedure, to pursue complete recanalization. Here we present a case series analysis of intra-arterial alteplase administration (5 mg bolus, repeated up to 15 mg if Thrombolysis in Cerebral Infarction (TICI) scale ≥2c is not achieved) in 15 consecutive anterior circulation stroke patients after unsuccessful thrombectomy, defined as TICI score ≤2b after at least 3 passes or if unsuitable for further endovascular attempts, with the aim of improving recanalization. An improvement of final TICI score was achieved in 10 of 15 patients (66.7%). TICI score ≥2c was achieved after 5 mg intra-arterial tissue plasminogen activator (iaTPA) in 4 patients, and after 10 mg iaTPA in 5 cases. Six of 15 patients received 15 mg iaTPA: 1 of 6 showed angiographical improvement. A major effect of intra-arterial alteplase was observed for distally migrated emboli. None of the patients experienced any symptomatic hemorrhagic transformation or other major bleeding. Our report shows, in a very small cohort, a high rate of final TICI score improvement, encouraging the development of randomized controlled trials of rescue intra-arterial thrombolysis in patients with suboptimal angiographic results after mechanical thrombectomy.