A total of 28 stents were implanted in 24 patients, with 4 patients receiving bilateral stents. Of the 28 stents, 13 (46.4%) were drug eluting and 15 (53.6%) bare metal. The median imaging follow-up for the entire cohort was 15 months (IQR 7.3–36.7) and the median clinical follow-up was 25.5 months (IQR 6.5–37.5).
The contralateral vertebral artery origin demonstrated atherosclerotic disease in 20 of the 24 patients. The four patients with no disease on the contralateral side had the ipsilateral (diseased) vertebral artery terminating in an isolated posterior inferior cerebellar artery with corresponding neurological symptoms.
Procedural success as determined by the ability to accurately deploy the stent was achieved in all procedures without any technical complications. There were no intraprocedural or post-procedure neurological complications observed either clinically or on imaging. A retroperitoneal hemorrhage requiring transfusion was observed in one patient, without any permanent sequelae. All patients remained on single or dual antiplatelet treatment after the procedure. Table 1 and Table 2 summarize the stent and patient characteristics for the bare-metal and drug-eluting groups, respectively. There was one case of stent kinking with subsequent complete occlusion.
For all patients, restenosis was seen in 8 out of 28 stents (28.6%). There was no statistically significant difference between the bare-metal and drug-eluting stent groups in terms of restenosis. Two patients (7%) had complete occlusion (one in each group) of the stent on follow-up. One of these occluded at 3 months and the other at 55 months. None of the restenosis or reocclusion events were symptomatic. There were no preprocedure or demographic factors that could be significantly correlated to restenosis. Table 3 gives a comparison of the two groups. The only statistically significant difference was in the stent diameter between the BM and the DE groups, with the mean diameter of the DE stents being smaller than the BM stents (p<0.0001), however the stent diameter did not have an impact on the restenosis rate. This was probably because the maximum available diameter of the DES was 4 mm and any vessel with a larger normal diameter was treated with a bare-metal stent. All patients demonstrated neurological improvement without recurrent symptoms in the same vascular territory.