Endovascular Therapy for Symptomatic Intracranial Artery Stenosis: a Systematic Review and Network Meta-analysis

Intracranial artery atherosclerotic stenosis (ICAS) is one of the most common causes of stroke. Endovascular therapy including balloon angioplasty alone (BA), balloon-mounted stent (BMS), or self-expanding stent (SES) was an important alternative to treat symptomatic ICAS refractory to medical treatment, while none of the three subtypes has been established to be the primary option. We conducted a systematic review and network meta-analysis to determine both the safety and efficacy and establish a hierarchy of different endovascular therapies on symptomatic ICAS. Major databases including MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for studies comparing outcomes of three different endovascular approaches and other comparable non-endovascular therapies for symptomatic ICAS patients published from 1 January 2000 to 1 November 2021. Primary outcomes included short-term mortality or stroke rate (peri-procedural, or mean follow-up ≤ 3 months), and long-term mortality or stroke rate (mean follow-up ≥ 6 months). Pairwise and network meta-analyses based on the above systematic review were conducted. A total of 19 eligible studies involving 3386 patients treated with 4 different approaches (BA, SES, BMS, and medical treatment) were analyzed. For primary outcome, BA had the highest ranking (SUCRA value 78), followed by BMS (SUCRA value 21.5) and SES (SUCRA value 13.1). The short-term mortality or stroke rate was significantly lower in the BA group compared to SES (OR = 2.50; 95% CI 1.12 to 5.57; p = 0.026) or BMS (OR = 0.43; 95% CI 0.19 to 0.96; p = 0.038). Other primary and secondary outcomes were no different among all three types of endovascular therapy. Overall, the studies were of good methodological quality and the consistency was acceptable across all network meta-analyses. BA offers the highest level of safety outcomes in terms of short-term mortality or stroke in treating symptomatic patients with intracranial artery stenosis, compared to SES and BMS, which needs to be confirmed in future studies. Trial registration in PROSPERO database: CRD42018084055.