Sir, Tsutsumi et al. reported the clinical and angiographic data on 12 patients receiving stent deployment for symptomatic ostial vertebral artery (VA) stenosis [1]. The in-stent re-stenosis (ISR) rate was surprising low – 0% angiographic restenosis at 12 months and 8% after a mean of 31.5 months clinical/radiological follow-up. These results are different from our previous observation on bare-metal stenting at VA ostiium, where the ISR rate was 28% after a mean angiographic follow-up time of 11.7 months [2]. In addition, the ISR rates in other reported series were also higher, ranging from 10 to 43% [3, 4]. We have several major concerns regarding the study of Tsutsumi et al. Firstly, the case number was only 12, limiting significantly its clinical relevance. Secondly, the authors did not describe the duration and regimen of anti-platelet medication (as clopidogrel was not approved in Japan), and this may have influenced the ISR rate [5, 6]. Thirdly, most ISR cases were asymptomatic and may have been undetected by clinical follow-up only. Conflict of interest statement We declare that we have no conflict of interest.