Purpose: To evaluate the safety and efficacy of the Misago self-expanding rapid-exchange nitinol stent system for the treatment of femoropopliteal occlusive disease in a prospective multicenter observational trial (ClinicalTrials.gov; identifier NCT01118117).
Methods: Between April and October 2008, the registry enrolled 744 patients (496 men; 69 ± 10 years) who had symptomatic ≥ 70% stenosis or occlusion of the superficial femoral or popliteal arteries treated with the Misago stent. Mean length of the 750 lesions was 63.9 mm; 282 (37.6%) vessels were completely occluded. Primary study endpoints were the need for target lesion revascularization (TLR) and event-free survival rates for the assessment of efficacy and safety, respectively. At 6 and 12 months post intervention, clinical symptoms of recurrent ischemia and/or claudication, Rutherford category, and ankle-brachial index (ABI) at rest were assessed.
Results: In the study period, 945 stents were successfully deployed in the 750 lesions. The overall TLR rate was 10.1% among 671 (90.3%) patients evaluated at 1 year [3.1% among 709 (95.3%) patients at 6 months]. Event-free survival at 12 months was 84.9%. Mean ABIs improved by ≥ 0.1 in three quarters of the patients (76.0%) over 12 months. The Rutherford grade improved or remained stable in the majority of patients (95.5%) after 1 year. Stent fractures (13 grade 1, 2 grade 2) in 3.1% of stents examined radiographically (n=484) at 1 year were not related to any clinical events. Primary patency was recorded in 574 (87.6%) patients evaluated at 1 year post procedure.
Conclusion: The Misago rapid-exchange nitinol stent showed promising efficacy and safety results, with a low stent fracture rate, in patients with femoropopliteal disease, making it a safe and reliable treatment option.