Comparing the Impact of Stenting vs. Medical Therapy for Intracranial Arterial Stenosis : A Systematic Review and One-stage and Two-stage Meta-Analysis of Randomized Clinical Trials.

PURPOSE: In the treatment of intracranial arterial stenosis (ICAS), controversies remain regarding the optimal treatment strategy. Our study aims to conduct an individual patient-level data meta-analysis of existing RCTs comparing PTAS versus best medical therapy and to identify differences in outcomes such as incidence of ischemic stroke or death. METHODS: Randomised controlled trials comparing the outcomes of stenting versus best medical therapy for patients who had symptomatic ICAS of >50%. Excluded studies included case reports, case series, reviews, observational studies,  letters or studies evaluating isolated angioplasty techniques without stenting. Data was extracted in accordance with PRISMA guidelines. RESULTS: 7 studies involving 1425 participants were included. There was an increased risk in the incidence of stroke and death within the first 30 days post-procedure for patients treated with PTAS over best medical therapy (RR = 2.22 [1.28-3.86], I²â€¯= 0%). Patients who underwent stenting also had a significantly higher risk of intracranial haemorrhage (RR = 12.66 [2.41-66.45], I²â€¯= 0%) and death (RR = 5.41 [1.20-24.28], I²â€¯= 0%).Under the shared frailty model, stenting when compared to medical therapy has a HR of 1.81 (95% CI:1.25-2.6) of stroke or death across 1 year. Under the parametric Royston-Parmar model, stenting has a significant decrease in the RMST(-0.83 months; 95% CI: -1.30-0.37). Stenting continued to show worse outcomes up to the 3 year mark with a HR of 1.60 (95% CI: 1.11-2.32). CONCLUSIONS AND RELEVANCE: There is an increased risk of peri- and post-procedural stroke and death over best medical therapy in patients with symptomatic ICAS who undergo PTAS. Further work is required to refine patient selection and mitigate peri-procedural risks.