Evaluation of safety and efficacy of the S.M.A.R.T.® Flex Vascular Stent System (OPEN study)

Objectives: The OPEN study evaluated the safety and efficacy of the S.M.A.R.T.® Flex Vascular Stent System in patients with femoropopliteal arterial disease.

Background: Long-term data on endovascular treatments of femoropopliteal arterial disease are required to establish the repair durability.

Methods: The OPEN study was a multicenter, single-arm, prospective study comparing primary safety and efficacy outcomes to performance goals (PG) developed for bare nitinol stents. Patients with symptoms due to a single, ≤180 mm length, de novo femoropopliteal arterial lesion with >70% stenosis were enrolled and followed for 36 months. Subjects with lesions ≤150 mm served as the initial comparison cohort for the PG (other cohorts were analyzed if the PG was met).

Results: 257 subjects with lesions ≤180 mm were enrolled. The mean lesion length was 71 ± 46 mm, and 52.5% had severe claudication. The primary safety endpoint (freedom from all-cause death, index limb amputation, and target lesion revascularization [TLR] through 30 days) was met in 98.8% (96.5%, 99.6%) of subjects in the comparison cohort, meeting the PG (88.0%). The primary efficacy endpoint (comparison cohort vessel patency at 12 months) was 68.4% (61.1%, 74.8%), where the lower limit of the 95% confidence interval did not meet the 66.0% PG. Freedom from TLR in the per-protocol cohort at 12-, 24-, 36-month was 84.7%, 74.6%, and 72.8%, respectively. The 24-month stent fracture rate was 4.3%, with no new fractures identified at 36 months.

Conclusion: The results show promising long-term safety and effectiveness for the S.M.A.R.T.® Flex Vascular Stent System in patients with femoropopliteal arterial disease.