Reperfusion strategies in stroke due to isolated cervical internal carotid artery occlusion: systematic review and treatment comparison

Introduction: Despite intravenous thrombolysis (IVT) and endovascular treatment (EVT) have been demonstrated effective in acute ischemic stroke (AIS) due to large vessel occlusions, there are still no conclusive data to guide treatment in stroke due to cervical internal carotid artery (ICA) occlusion. We systematically reviewed available literature to compare IVT, EVT, and bridging (IVT + EVT) and define optimal treatment. Methods: Systematic review followed predefined protocol (Open-Science-Framework osf.io/bfykj). MEDLINE, EMBASE, and Cochrane CENTRAL were searched. Results were restricted to studies in English, with sample size ≥ 10 and follow-up ≥30 days. Primary outcomes were favorable outcome (mRS ≤ 2), mortality, and symptomatic intracerebral hemorrhage(sICH), defined according to study original report. Newcastle-Ottawa scale was used for bias assessment. Results: Seven records of 930 screened were included in meta-analysis. Quality of studies was low-to-fair in 5, good in 2. IVT (n = 450) did not differ for favorable outcome and mortality compared to EVT (n = 150), though having lower rate of sICH (OR = 0.4, 95% CI 0.2–0.8). Compared to IVT, bridging (IVT + EVT) was associated with higher rate of favorable outcome (OR = 2.2, 95% CI 1.3–3.7). Compared to EVT, bridging (IVT + EVT) provided higher rate of favorable outcome (OR = 1.9, 95% CI 1.1–3.4), with a marginally increased risk of sICH (OR = 2.1, 95% CI 1–4.4) but similar mortality rates. Conclusions: Our systematic review highlights that, in acute ischemic stroke associated with isolated cervical ICA occlusion, bridging (IVT + EVT) might lead to higher rate of functional independence at follow-up, without increasing mortality. The low quality of available studies prevents from drawing firm conclusions, and randomized-controlled clinical trials are critically needed to define optimal treatment in this AIS subgroup.