Objective Our aim was to compare the clinical outcome of patients with ischaemic stroke with anterior large vessel occlusion treated with stent retrievers and/or contact aspiration mechanical thrombectomy (MT) under general anaesthesia (GA) or conscious sedation non-GA through a systematic review and meta-analysis.

Methods The literature was searched using PubMed, Embase and Cochrane databases to identify studies reporting on anaesthesia and MT. Using fixed or random weighted effect, we evaluated the following outcomes: 3-month mortality, modified Rankin Score (mRs) 0–2, recanalisation success (thrombolysis in cerebral infarction (TICI) ≥2b) and symptomatic intracerebral haemorrhagic (sICH) transformation.

Results We identified seven cohorts (including three dedicated randomised controlled trials), totalling 1929 patients (932 with GA). Over the entire sample, mortality, mRs 0–2, TICI≥2b and sICH rates were, respectively 17.5% (99% CI 9.7% to 29.6%; Q-value: 60.1; I²: 93%, 1717 patients), 42.1% (99% CI 33.3% to 51.7%; Q-value: 41.3; I²: 87.9%), 82.9% (99% CI 74.0% to 89.1%; Q-value: 20.7; I²: 80.6%, 1006 patients) and 5.5% (99% CI 2.8% to 10.8%; Q-value: 18.6; I²: 78.5%). MT performed in non-GA patients was associated with better 3-month functional outcome (pooled OR, 1.35; 99% CI 1.04 to 1.76; Q-value: 24.0; I²: 9.2%, 1845 patients) and lower 3-month mortality rate (pooled OR, 0.70; 99% CI 0.49 to 0.98; Q-value: 1.4; I²: 0%, 1717 patients; fixed weighted effect model) compared with GA. MT performed under conscious sedation non-GA had significantly shorter onset-to-recanalisation and onset-to-groin delay compared with GA, and recanalisation success and sICH were similar.

Conclusion Non-GA during MT for anterior acute ischaemic stroke with current-generation stent retriever/aspiration devices is associated with better 3-month functional outcome and lower mortality rates. These unadjusted estimates are subject to biases and should be interpreted with caution.