A meta-analysis and systematic review of endovascular thrombectomy versus medical management for acute basilar artery occlusion

Objective: Acute basilar artery occlusion (BAO) is a devastating neurologic event. As endovascular thrombectomy (EVT) became more prevalent for anterior circulation strokes, investigations were conducted in the posterior circulation. Its success in improving outcomes compared to standard medical therapy (SMT) after BAO has been debated.Methods: We conducted a systematic review and meta-analysis of all randomized controlled trials (RCTs) and observational cohort studies evaluating EVT compared to SMT in acute BAO. We queried PubMed, Embase, and Cochrane for studies. Primary outcome was good functional outcome at 90 days (modified Rankin scale (mRS) <= 3). We analyzed studies for risk of bias (ROB) and calculated pooled risk ratios (RRs), odds ratios (ORs), and mean differences (MDs) with 95% confidence intervals (95%CI) using the random effects model for our primary outcome and secondary positive outcomes and harms. Results: We identified four RCTs (991 patients randomized) and three cohort studies (1030 patients treated in -trial) that fit inclusion criteria. Three RCTs had low ROB, one had serious ROB. One cohort study had high ROB, one had moderate ROB, and one had low ROB. EVT was statistically significantly more associated with good functional outcome than SMT in RCTs (RR=1.54, 95%CI=1.16-2.04, p = 0.003) and trended towards significance in cohort studies (RR=2.64, 95%CI=0.87-8.00, p = 0.09). Mean mRS at 90 days was lower in EVT patients in RCTs (MD=-0.65, 95%CI=-1.07--0.22, p = 0.003) though not cohort studies (MD =-0.84, 95% CI=-2.48-0.79, p = 0.31). Symptomatic intracerebral hemorrhage (sICH) was statistically significantly associated with EVT in RCTs (OR=6.36, 95%CI=2.24-18.07, p < 0.001) and statistically non-significantly in cohort studies (OR=4.51, 95CI=1.00-20.33, p = 0.05). Mortality at 90 days was statistically lower with EVT than with SMT in both RCTs (OR=0.76, 95%CI=0.65-0.88, p < 0.001) cohort studies (OR=0.36, 95%CI=0.26-0.50, p < 0.001) Conclusion: EVT is associated with greater rates of good functional outcomes and lower rates of death and disability despite higher rates of periprocedural sICH.