Johannes Lammer, Vienna, Austria, presented preliminary data from the VIASTAR study at CIRSE 2010. In the trial, the Viabahn Endoprosthesis (Gore) is compared to bare metal stents in TASC C and D lesions.
“Bare stent technology has been tested in short superficial femoral artery lesions (TASC A and B) has been shown to be superior to percutaneous angioplasty in two randomised controlled trials. The old Viabahn endoprosthesis has shown promising patency rates in long superficial femoral artery lesions, but the vibrant study failed to demonstrate superiority over bare stents at one and two year follow-up. But, the new Viabahn with heparin-bonding technology and contoured edge has shown less target lesion revascularisation and restenoses so far,” Lammer said. The Viastar study is a prospective, randomised, multicentre European study, conducted independently of the company. Its objective is to evaluate the performance of Viabahn Endoprosthesis with propaten bioactive surface (5–8 mm devices) and compare their efficacy to bare nitinol stents in treating long lesion superficial femoral arterydisease (lesions 10 –27 cm).
The primary efficacy endpoint for the study is primary patency measured at one year post-procedure by colour Doppler ultrasound and CT angiography or digital subtraction angiography. The primary safety endpoint is a composite of serious procedural (30-day) adverse events, including death, myocardial infarction, study limb amputation, and access site and treatment site complications requiring surgery or blood transfusion.
Secondary endpoints include technical and clinical success, primary and secondary patency at one and two years and target lesion revascularisation and target lesion revascularisation at one and two years
Lammer told delegates that 98 patients with a mean age 67.9 years (45–85), 69 of whom were male were enrolled in the study. The mean lesion length 21.6 cm (10–32), and mean lesion diameter was 5.4mm. 51 patients got Viabahn and 47 were treated with the nitinol stent.
At six months follow-up, there were 40 patients and at 12 months data from 12 patients. Data from these contributed to the preliminary results.
Lammer told delegates that with the Viabahn Endoprosthesis, there were two instances of target lesion revascularisation. These were due to active thromboses due to discontinuation of Plavix, and one asymptomatic stenosis which was greater than 50%. On the other hand, with the nitinol stent, there was one occlusion, four cases of target lesion revascularisation due to in-stent restenosis and one case of asymptomatic in-stent restenosis (greater than 50%).