Twelve-Month Results of the Nitinol Astron Stent in Iliac Artery Lesions

To evaluate the safety and efficacy of a self-expanding bare-metal nitinol stent (Astron; BIOTRONIK AG, Bülach, Switzerland) for the treatment of atherosclerotic lesions in the common and external iliac arteries. This study tested the hypothesis that the major adverse event (MAE) rate at 12 months was less than or equal to a performance goal of 15%.

In a prospective study that began in November 2011, 161 patients with symptomatic iliac lesions were treated with an Astron stent in the United States, Canada, and Austria. The primary endpoint was a composite rate of procedure- and stent-related MAEs at 12 months that included 30-day mortality, clinically indicated target lesion revascularization (TLR), and index limb amputation.

The MAE rate at 12 months was 2.1% (3/146; [95% CI: 0.4% to 5.9%]; p < 0.001). The acute procedural success and 30-day clinical success outcomes were both 95% (153/161). The primary patency rate at 12 months was 89.8% (115/128). The comparison of baseline and 12-month Ankle Brachial Index (ABI) measurements showed a mean increase of 0.23 ± 0.19 (p < 0.001). The Walking Impairment Questionnaire (WIQ) PAD specific score, walking distance score, walking speed score and stair climbing score paired each showed a significant increase from baseline to 12 months (p<0.001).

The Astron stent system was shown to be safe and effective in the treatment of patients with atherosclerotic disease. The observed MAE rate met the pre-specified performance goal of 15%. The stent demonstrated a high 12-month primary patency rate and showed improvement in quality of life measures.