Drug-coated balloon versus bare-metal stent for the treatment of symptomatic vertebral artery origin stenosis: a systematic review and meta-analysis

Symptomatic vertebral artery origin stenosis (VAOS) is associated with high recurrent stroke risk despite medical therapy. While bare-metal stents (BMS) are established for endovascular treatment, in-stent restenosis remains common. Drug-coated balloons (DCB) offer a stent-free alternative, but comparative effectiveness is uncertain. We searched PubMed, Embase, the Cochrane Library, Web of Science, and Scopus for comparative studies of DCB vs. BMS in symptomatic VAOS. The primary outcome was imaging-confirmed restenosis; secondary outcomes included symptomatic restenosis, technical success, periprocedural complications, and follow-up cerebrovascular events. Subgroup (study type, VAOS severity, imaging modality: digital subtraction angiography DSA-based vs. non-DSA-based) and sensitivity analyses were performed. Four studies (2 randomized controlled trials RCTs, 2 cohort studies) involving 329 patients (165 DCB, 164 BMS) were included. DCB significantly reduced imaging-confirmed restenosis (risk ratio RR = 0.45; 95% confidence interval CI: 0.27–0.73), with benefits in RCTs (RR = 0.44, 95% CI: 0.25–0.77), severe VAOS (≥ 70%; RR = 0.39, 95% CI: 0.22–0.70), and DSA-based follow-up (RR = 0.36, 95% CI: 0.19–0.68). No between-group differences were observed in secondary outcomes. Sensitivity analysis indicated that the primary result was highly influenced by the largest RCT, with limited robustness. In this hypothesis-generating meta-analysis, DCB is associated with lower rates of imaging-confirmed restenosis than BMS in symptomatic VAOS, with comparable safety. These are preliminary findings limited to four small-sample studies from a single country and should not be used to guide routine clinical selection. Large, multicenter, long-term follow-up RCTs are required to confirm these results.