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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.