Lammer from the University Hospital Vienna, Austria, said that the preliminary data from the VIASTAR trial show a trend towards a higher in-stent restenosis/occlusion rate with bare metal stents. However, he noted that edge restenosis of the Viabahn (Gore) endoprostheses can still be seen.
The VIASTAR trial is based on the hypothesis that the Viabahn endoprosthesis (with bioactive propaten surface) will result in greater mid- and long-term patency of the treated arterial lesion compared to bare nitinol stents, when the use of both devices is compared in the treatment of chronic long superficial femoral artery lesions.
The mean lesion length in the bare metal stent group was 20.1cm (10–34). There were 21 TASC B lesions, 27 TASC C lesions and 19 TASC D lesions. The mean diameter of the vessels was 5.4mm (4.5–6.5). In the group of patients receiving Viabahn, the mean length of the lesions was 24.1cm (10–35). In this group, there were 20 lesions classified as TASC B+, 26 that were classified as TASC C and 25 that were TASC D. The mean diameter was 5.4mm (4.5–6.5).
Preliminary efficacy was measured by colour Doppler ultrasound. Six-month data was available for 55/67 patients in the bare metal stent group and 53/71 in the Viabahn group. At this time point, there were seven instances of target lesion revascularisation in the bare metal stent group and three in the Viabahn group. There were two occlusions in the bare metal stent group and five in the Viabahn group, and eight cases of target lesion revascularisation vs. four in the Viabahn group. There was one bypass in the Viabahn group and none in the other.
Data were available for 33/67 patients in the bare metal stent group and 38 out of 71 patients in the Viabahn group at the one year mark.
Investigators noted that there were 17 cases of ≥50% restenosis in the bare metal stent group and three cases in the Viabahn group. There were five cases of occlusion in the bare metal stent group and nine cases in the Viabahn group. There were 13 instances of target lesion revascularisation in the bare metal stent group and 28 cases in the Viabahn group. There were no instances of bypass in the bare metal stent group and two in the Viabahn group.
“In the Viabahn group, there were nine occlusions and three stenoses at the 12 month follow-up. The mean diameter was 5.4mm and the mean length was 228mm.
In the bare metal stent group, there were five occlusions and 17 cases of stenosis at follow-up. The mean diameter was 5.4mm and mean length was 210mm,” said Lammer.
